To prepare the crust, put flour, sugar and salt in the food processor fitted with the dough blade and pulse a few times to mix.
Cube the butter and add to the flour mixture. Make sure butter is cold. Pulse several times until butter is about pea size and mixture resembles coarse crumbs.
Add cold water, 1 tablespoon at a time, and pulse until the dough just starts to pull together.
Turn the dough out on a lightly floured board and shape into a disk. Wrap in plastic and rest in the refrigerator for an hour.
Roll the dough out to about 1/8” thick. Use a 2” round cookie cutter and cut into 28 pieces.
Beat the egg and milk or water together to make the egg wash.
Place one dough circle on a lined baking sheet. Brush egg wash over the rim of the circle and place a rounded 1/2 teaspoon of cookie butter in the middle. Place a cake pop stick in the middle of the cookie butter so that the top of the cake pop stick is right in the center of the circle. Take a second circle and place it over the top, use a fork to seal the border of the pie.
Repeat until you have 14 pie pops all filled and sealed up. Refrigerate remaining egg wash, you’ll need it later.
Place the baking sheet in the freezer or refrigerator if your freezer is not big enough.
Preheat the oven to 400°F.
Take baking sheet out of the freezer and brush egg wash all over the top of each pie. Mix the 2 tablespoons of sugar with the 1/2 teaspoon of cinnamon and sprinkle liberally over the top of each pie.
Bake for 15 minutes.
Remove from the oven, let cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.