In a bowl of a stand mixer with the paddle attachment OR an electric mixer, cream softened butter or coconut oil, vanilla, and coconut sugar until light and fluffy.
In a separate bowl, mix together the flour and baking powder.
Slowly add the dry mixture to the wet mixture and mix until crumbly, then add milk and keep mixing until mixture forms a dough ball.
Roll out dough right away to ⅛" thick. (do not refrigerate). If you do decide to keep it in the fridge, be sure to warm up to room temperature BEFORE rolling. The dough will crumble when you roll it if you put it in the fridge.
Use a cookie cutter to cut out cookies.
Bake cookies for 10-15 minutes, or until light golden brown.
Remove from oven and let cool entirely before removing from the pan.
For the Peanut Butter Filling
In a stand or electic mixer, whisk all ingredients until light and fluffy.
Pipe filling onto cookies, then place in fridge to set for about 30 minutes.
Chocolate coating
In a heat-safe bowl, melt chocolate chips and coconut oil in 30 second increments, mixing in between, until smooth and shiny.
Dip each cookie in melted chocolate and let set in the fridge.
Store cookies in an air-tight container in the fridge in layers with parcment paper.