01 -
Set your oven to 350 degrees Fahrenheit (175 Celsius). Line a muffin tray with paper cups to keep things from sticking and make it easy to take them out.
02 -
Grab a big bowl and beat the butter with both sugars until soft and fluffy. Stir in the egg if you want and the vanilla until mixed in. Slowly add the flour and mix until dough forms.
03 -
In another bowl, mix the peanut butter with powdered sugar until smooth. Roll into 24 to 30 small balls. Pop them in the fridge for about 10 minutes so they firm up.
04 -
Press some dough into each muffin cup creating a little hole in the center. Toss a chilled peanut butter ball into each hole. Throw chocolate chips and any extras on top. Cover a bit with the leftover dough.
05 -
Brush the top of each cookie bite with the egg yolk and water mix so they'll bake up golden and shiny.
06 -
Put them in the oven for 12 to 15 minutes until the edges get a light golden color and the centers look set.
07 -
Let the bites cool in the pan for 5 minutes then move them to a wire rack. The peanut butter inside will be melty warm but will firm up once cooled.