Preheat your oven to 350°F (175°C). Line an 8x8 square pan with parchment paper and butter it generously.

In a microwavable bowl, melt 1/2 cup of butter and 3/4 cup of chocolate chips until smooth.

Stir in the sugar, vanilla, and instant espresso.

In a separate small bowl, whisk the eggs until bubbly on top, about 1 minute, and then add them to the chocolate mixture.

In another small bowl, sift together the flour, cocoa powder, baking powder, and salt. Add the dry ingredients to the wet ingredients and mix until just combined. Stir in the remaining chocolate chips.

Spread the brownie batter evenly into the prepared pan and bake for 25-30 minutes. A cake tester should come up with a couple of crumbs.

Let the brownies cool. Once cool, cut them into 9 squares.

For the frosting, use a stand mixer fitted with a whisk attachment. Add the room temperature butter and powdered sugar, mixing on low speed until blended. Increase to medium speed and beat for about 3 minutes.

Add vanilla and milk, continuing to beat for one more minute, adding a bit more milk if needed for spreading consistency. Refrigerate the frosting until ready to use.

Pipe the frosting over the brownies in a zigzag motion to mimic a mummy wrap and attach two candy eyes to each brownie.