01 -
Preheat oven to 350°F (175°C). Line a standard muffin tin with paper liners to ensure cookie bites release easily after baking.
02 -
In a large mixing bowl, cream together the softened unsalted butter, brown sugar, and granulated sugar until light in color and fluffy. Add the egg if using, along with vanilla extract, and blend well. Gradually mix in all-purpose flour until a smooth, soft dough forms.
03 -
In a separate small bowl, combine creamy peanut butter with powdered sugar and beat until fully integrated and smooth. Divide this filling into 24 to 30 evenly sized balls and refrigerate for approximately 10 minutes to firm up.
04 -
Scoop tablespoon-size portions of cookie dough and flatten lightly. Press a chilled peanut butter ball in the center of each portion, then gently wrap the dough around the filling to enclose completely. Place in the prepared muffin tin. Sprinkle semi-sweet chocolate chips and optional toppings over each cookie bite.
05 -
Brush the surface of each cookie bite with the egg yolk and water mixture to encourage a deep golden color during baking.
06 -
Place muffin tin in the preheated oven. Bake for 12 to 15 minutes, or until cookie edges are gently golden and centers are just set.
07 -
Allow cookie bites to cool in the tin for about 5 minutes, then transfer to a wire rack. The peanut butter center will remain soft while warm and become firmer upon cooling.