In a light-colored pan, melt 1 cup of butter over medium-high heat. Stir occasionally and cook for about 5 minutes, until brown bits form at the bottom of the pan. Remove from heat and let it cool for 20-30 minutes.

Preheat your oven to 350°F and line a baking sheet with parchment paper.

In a mixing bowl, combine the cooled brown butter, granulated sugar, and brown sugar. Beat until light and fluffy.

Add in the egg and mix until fully incorporated. Then, add the egg yolk and vanilla extract.

In a separate bowl, whisk together the flour, salt, and baking soda. Gradually mix the dry ingredients into the wet ingredients until just combined. Do not overmix.

Scoop about 2 tablespoons of dough, roll into balls, and place them on the prepared baking sheet.

Bake for 9-10 minutes, or until the edges are golden brown while the center remains soft. Allow the cookies to cool completely.

In a microwave-safe bowl, heat the chocolate chips and heavy cream in 30-second intervals, stirring between each, until the chocolate is fully melted and smooth.

Spread a thin layer of crunchy peanut butter over each cooled cookie.

Spoon the chocolate ganache on top of the peanut butter layer. If the peanut butter is too soft, freeze the cookies for 5 minutes before adding ganache.

Sprinkle chopped peanut butter cups on top of the ganache.

Let the ganache set, or enjoy immediately for a gooey, decadent treat!