Pre-heat the oven to 350∞F.

Butter a 9x9 baking dish.

In small saucepan over low heat, melt butter completely. Stir in sugar and continue cooking for 1-2 minutes, stirring constantly. Do not allow sugar mixture to boil.

Pour butter mixture into a large bowl or stand mixer, beat in cocoa powder, eggs, salt, baking powder, espresso powder, and vanilla extract. Mix until well combined.

Stir in the flour until well combined.

Spread into prepared pan (batter will be very thick and sticky). Place the 9 creme eggs in rows of three in the batter. Press them down and use a butter knife or rubber spatula to spread the batter up over the eggs.

Bake for about 25 minutes exactly. The edges should be set and the center should still look slightly moist, but not uncooked. Cool on a wire rack before cutting.