– 1 cup unsalted butter , plus additional for greasing pan
– 1 cup creamy peanut butter
– 1 teaspoon pure vanilla extract
– 16 ounces (1 lb or about 3 ¾ to 4 cups) powdered sugar, unsifted
Butter the bottom and sides of an 8- x 8-inch pan, then line with parchment paper. Microwave the butter & peanut butter. Stir in the vanilla and confectioners' sugar with a wooden spoon or rubber spatula until evenly combined. Pour the mixture into the prepared pan and spread into an even layer.