Cream butter, add in icing sugar
Beat in yolk one at a time, followed with essence
Add in flour, knead
Divide into 4
Knead in 1 tbsp each creamy PB to each dough portion
Scoop with ice cream/cookie scoop, shape into rounds
Make indentation in center with the end of a rolling pin
Place a couple of choc chips
Bake on preheated 350 F for 8-10 mins (depending your oven it can be 10-12 mins)
Cool on sheet for 5 mins, move to cooling rack