These Kit Kat brownies pair a rich, cocoa-forward brownie with crisp chocolate-covered wafer pieces tucked inside and scattered on top. The candy adds a little crunch to the fudgy center, while a short cooling period helps the bars set so they slice neatly.
Ingredients
- 1 cup (226 g) unsalted butter, cut into pieces
- 1 1/4 cups (250 g) granulated sugar
- 3/4 cup (150 g) packed light brown sugar
- 1 cup (85 g) unsweetened cocoa powder, natural or Dutch-process
- 3 large eggs (about 150 g without shells), at room temperature if convenient
- 2 teaspoons (10 ml) vanilla extract
- 1 cup (125 g) all-purpose flour, spooned into the measuring cup and leveled
- 1/2 teaspoon (3 g) fine salt
- 1 cup (170 g) semisweet chocolate chips
- 6 standard Kit Kat bars, about 1.5 ounces (42 g) each or 252 g total; chop 4 for the batter and 2 for the top
Instructions
- Heat the oven to 350°F (175°C). Line a 9-by-13-inch (23-by-33-cm) metal baking pan with parchment paper, leaving a little overhang on the long sides so you can lift out the brownies later. Lightly grease the exposed sides of the pan. A metal pan gives the edges a more even bake; if using glass, start checking a few minutes earlier because it can retain heat differently.
- Put the butter in a medium microwave-safe bowl and melt it in short bursts, stirring between each, or melt it gently in a small saucepan. It should be liquid but not sizzling. Whisk in both sugars and the cocoa powder until evenly combined. The mixture will look thick and slightly grainy; that is normal. Let it cool for about 5 minutes so the eggs will not begin to cook when added.
- Whisk in the eggs one at a time, mixing well after each addition, then stir in the vanilla. Keep whisking until the batter looks glossy and a little thicker. This step helps the sugar and eggs form a cohesive base, but there is no need to beat air into the mixture as you would for a sponge cake.
- Add the flour and salt. Fold with a flexible spatula just until no dry flour remains, scraping the bottom and sides of the bowl. Stop as soon as the mixture is uniform; overmixing after the flour goes in can make brownies tougher rather than tender. Fold in the chocolate chips and the four chopped Kit Kat bars, distributing the larger pieces through the batter without crushing every wafer.
- Scrape the batter into the prepared pan and spread it into an even layer, pushing it gently into the corners. Scatter the remaining two chopped Kit Kat bars over the surface and press the pieces in lightly so they stay in place. Leave some pieces visible for a crunchy top, but avoid piling them all in the center, where they can make that area bake unevenly.
- Bake for about 32 minutes, beginning to check at 29 minutes because ovens and pans vary. The edges should look set and the center should no longer appear liquid, though it can remain soft. Since this batter contains eggs, check the brownie crumb in the center with a food thermometer, avoiding a chocolate chip or candy piece: the USDA FSIS safe minimum temperature for egg dishes is 160°F (71°C). A toothpick may pick up moist crumbs or melted chocolate, which is expected; it should not come out coated in raw-looking batter.
- Set the pan on a cooling rack and leave the brownies in it for 2 hours before cutting. This cooling time is part of the recipe, not an optional shortcut: the warm chocolate and wafer pieces are soft, and the center firms as it cools. Use the parchment overhang to lift the slab onto a board, then cut into 16 squares with a sharp knife. Wipe the blade between cuts for cleaner edges.
Tips
- Measure flour lightly. Spoon flour into a dry measuring cup and level it rather than scooping straight from the bag. A packed cup adds too much flour and can turn a fudgy brownie dry or cakey. If using a scale, the listed 125 g is the most dependable amount.
- Keep the wafer pieces chunky. Chop the Kit Kat bars into roughly 1/2-inch (1-cm) pieces. Tiny crumbs disappear into the batter, while very large chunks can make the brownies harder to cut and create weak spots. A few crumbs are fine and can be folded in with the chunks.
- Do not judge doneness by a completely clean toothpick. That test can lead to overbaking, especially because melted chocolate sticks to the pick. Look for set edges and a center that has lost its wet shine, and use the thermometer guidance in the baking step for egg safety.
- Use a practical swap if needed. Salted butter can replace unsalted butter; omit the added salt or reduce it to a small pinch. If you do not have semisweet chips, use the same weight of chopped semisweet chocolate. Milk chocolate makes the brownies sweeter, while dark chocolate gives a more pronounced cocoa contrast.
Serving Suggestions
For tidy dessert squares, serve the brownies at room temperature after they have cooled fully. Their chocolate flavor and crisp wafer pieces are satisfying on their own, but a small scoop of vanilla ice cream makes a classic warm-and-cold pairing. If you want to serve them warm, heat individual portions briefly and expect the center and candy pieces to be softer rather than cleanly sliceable. A little unsweetened whipped cream or a few fresh strawberries can balance the richness without covering up the Kit Kat flavor.
For a party tray, cut the slab into 16 generously sized squares or make 24 smaller bites. The smaller portions work well alongside other desserts, since the brownies are rich. If preparing a platter ahead, keep the pieces in one layer or separate layers with parchment so the topping does not stick to neighboring bars. Add ice cream or whipped cream just before serving rather than storing it on top.
Variations
- More wafer crunch: Reserve an extra Kit Kat bar, about 1.5 ounces (42 g), and press its chopped pieces onto the brownies during the last 5 minutes of baking. Adding them late keeps more of the wafer texture distinct, though the pieces may not adhere as firmly as the baked-in topping.
- Nutty brownies: Fold in 1/2 cup (60 g) chopped toasted pecans or walnuts along with the chocolate chips. The nuts add a crisp, earthy contrast; make sure guests know they are included.
- Less sweet, deeper chocolate: Replace the semisweet chips with 1 cup (170 g) chopped dark chocolate and use Dutch-process cocoa. The cocoa gives a smoother, darker flavor, while the candy still contributes sweetness. Do not reduce the sugar substantially, since it affects the brownies’ moisture and texture as well as their sweetness.
- Different candy-bar topping: Replace some or all of the Kit Kat pieces with an equal weight of another crisp wafer chocolate bar. The texture and sweetness will vary by brand and filling, so keep the total candy amount close to 252 g for a similar balance.
Storage and Reheating
Once the brownies have cooled, store them in an airtight container. They can stay at room temperature for up to 3 days in a cool, dry place; the wafer pieces gradually soften as they absorb moisture from the brownie. For food safety, refrigerate them within 2 hours of baking or serving, especially if the room is warm. Refrigerated brownies keep for 3 to 4 days, though chilling makes the center firmer and the candy less crisp. Let a chilled square sit at room temperature for 15 to 20 minutes if you prefer a softer bite.
To freeze, wrap individual squares or the uncut slab tightly, then place it in a freezer-safe container for up to 2 months for best texture. Thaw wrapped brownies in the refrigerator overnight or at room temperature for about 1 to 2 hours. To warm one square, microwave it for 8 to 12 seconds, then add a few seconds only if needed; short bursts help avoid turning the wafer filling too hot or making the edges tough. The candy may soften after reheating, but the brownie remains enjoyable.
Frequently Asked Questions
Can I make Kit Kat brownies in an 8-by-8-inch pan?
That pan has considerably less surface area than a 9-by-13-inch pan, so the full batch will be much deeper and need a longer bake. For the most reliable result, use the pan size listed. If you choose the smaller pan, use about half the batter and begin checking around the original bake time; do not fill the pan to the rim.
Why did my brownies turn out dry?
The most common causes are too much flour or baking them too long. Weigh the flour if possible, and start checking before 32 minutes because oven temperatures vary. Brownies continue to set while cooling, so taking them out when the edges are firm and the center is just set helps preserve a moist middle.
Will the Kit Kat pieces stay crunchy after baking?
Some wafer crunch remains, but pieces baked inside soften somewhat as they sit in the moist brownie. The topping usually keeps more texture, especially when added near the end of baking. For the crispest contrast, reserve a few fresh chopped pieces and scatter them over the brownies just before serving.
Can I prepare the batter ahead?
It is better to bake the batter soon after mixing. Once the flour is incorporated, a long wait can affect the texture, and the candy may start to soften. Instead, bake the brownies, cool them completely, and store them covered; you can cut them closer to serving time for especially neat edges.
How can I tell when the brownies are done if my thermometer touches chocolate?
Move the probe to a spot in the center that looks like brownie crumb rather than a visible chip or candy piece. If the probe lands in melted chocolate, the reading may not represent the brownie itself. Check a second nearby spot, and use the set edges and non-liquid center as additional visual cues.
Can I use a boxed brownie mix?
Yes. Prepare a mix sized for a 9-by-13-inch pan according to its package directions, fold in about 1 cup (170 g) of chopped Kit Kat pieces, and scatter the remaining candy over the top. Follow the package baking time and check the center for doneness; the mix may produce a sweeter or cakier result than this cocoa-based recipe.
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Safety notes: safe minimum internal temperatures from USDA FSIS; raw and undercooked fish guidance from the U.S. FDA. Food safety notes
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