Ingredients
- 1/3 cup salted butter
- 1/3 cup creamy peanut butter
- 5 oz unsweetened baking chocolate, cut into chunks
- 1 3/4 cups granulated sugar
- 2 teaspoons vanilla extract
- 3 large eggs (room temperature)
- 1 cup all‑purpose flour
- 12 Reese’s Peanut Butter Cups
Ingredients and Why They Matter
Unsweetened baking chocolate gives a deep, pure chocolate base that you sweeten yourself with sugar, which tends to yield a richer brownie than cocoa alone. Salted butter adds richness and just enough salt to sharpen the chocolate and peanut butter flavors; because the recipe doesn’t include extra salt, using salted butter balances the sweetness.
Creamy peanut butter melted with the chocolate and butter infuses the brownie itself with peanut flavor, not just the center, creating a cohesive chocolate‑peanut butter profile in every bite. Granulated sugar provides sweetness, contributes to the shiny, crackly top when beaten with eggs, and helps keep the brownies moist and chewy.
Eggs are beaten with sugar until thick and fluffy, which helps give structure and that fudgy‑but‑not‑cakey texture. Room‑temperature eggs incorporate more smoothly, reducing mixing time and helping the batter emulsify. All‑purpose flour is kept to just 1 cup so the brownies stay dense and fudgy rather than cakey. Mixing only until combined limits gluten development.
Reese’s Peanut Butter Cups are the star: as they bake inside the batter, the chocolate softens and the peanut butter center becomes molten, creating a surprise pocket of candy in the middle of each brownie.
Step-by-Step Instructions
1. Prep the Pan and Oven
- Preheat the oven to 350°F (175°C).
- Generously spray a standard 12‑cup muffin tin with cooking spray, making sure to coat the bottoms and sides of each well; this helps the brownies release cleanly.
2. Melt Chocolate, Butter, and Peanut Butter
- In a small saucepan over low heat, combine the unsweetened baking chocolate chunks, salted butter, and creamy peanut butter.
- Stir constantly as they melt to prevent scorching; remove from the heat as soon as the mixture is smooth and fully melted.
- Let the mixture cool for about 5 minutes so it doesn’t scramble the eggs when you add it later.
3. Whip the Sugar, Eggs, and Vanilla
- In a large mixing bowl, add the granulated sugar, eggs, and vanilla extract.
- Using an electric mixer, beat on high speed for 2–3 minutes until the mixture is pale, thick, and slightly fluffy. This step incorporates air and helps create that crackly brownie top.
4. Combine Wet and Dry
- Pour the cooled chocolate–peanut butter mixture into the sugar‑egg mixture. Beat on low speed until just blended and uniform.
- Add the all‑purpose flour and mix on low speed until just combined, scraping the sides of the bowl as needed. Do not overmix; a few tiny streaks of flour are better than over‑working the batter.
5. Assemble the Stuffed Brownies
- Spoon about 1 tablespoon of brownie batter into each muffin cup, spreading it to cover the bottom.
- Place one Reese’s Peanut Butter Cup on top of the batter in each cup, pressing lightly so it nestles into the batter.
- Add roughly 1 teaspoon of brownie batter over each peanut butter cup and gently spread it so the candy is completely covered. Your Reese’s should be fully encased in batter.
6. Bake and Cool
- Bake the brownies for about 20 minutes. The tops should look set and slightly shiny, and a toothpick inserted along the edge (not through the center where the candy sits) should come out with moist crumbs, not wet batter.
- Remove the muffin tin from the oven and let the brownies cool in the pan until they’re firm enough to handle.
- Carefully run a thin knife around the edges if needed, then lift the brownies out and transfer to a cooling rack to cool completely.