Preheat the oven to 350℉/180℃. Grease an 8×8 inch square pan. For easy removal of the blondies, place parchment paper on the bottom and 2 sides of the pan. Grease again and then set side.
Melt the butter. As it cools, prep and measure the rest of your ingredients.
1/2 cup butter melted
In a large bowl, whisk together the slightly cooled melted butter and white sugar until well combined. You may use a whisk, or an electric mixer.
3/4 cups white sugar
Add in peanut butter, egg, egg yolk, and vanilla. Continue to whisk until well combined.
1/2 cup peanut butter creamy, 1 egg room temperature, 1 egg yolk room temperature, 2 tbsp vanilla
Toss in the flour, baking powder, and salt. Once it is almost completely mixed in, add the chopped mini eggs and continue mixing until no flour streaks appear and there is a soft dough.
1 cup all-purpose flour, 1/2 tsp baking powder, 1/2 tsp salt, 1/2 cup Reese's peanut butter mini eggs
Evenly press the dough into the prepared pan.
Gently press more mini eggs and globs of peanut butter on top of the blondies. This is optional.
Bake for 24-27 minutes. Mine took exactly 27 minutes.
Cool, slice, and enjoy!