When you're ready to roll out and form the cookies, remove 1 disk of dough from the fridge and let sit at room temperature until softened slightly, at least 30 minutes to 1 hour. Center a rack in the oven and preheat to 350 (F) and prepare 2 sheet pans by lining with parchment paper. Set aside.
Next, prepare your fillings. In a small jar with a lid, combine 12 Haribo gummy peaches and 1/3 cup vodka. Seal the jar tightly and give the jar a good shake; set aside. Check the consistency of your strawberry IPA jam — depending on how much alcohol your IPA had, the jam might not have thickened enough and will still be too runny for the cookies. If this is the case, stir 1 teaspoon unflavored powder gelatin into the chilled mixture and let sit for at least 15 minutes. The gelatin should thicken the mixture.
At this point, your dough should be good to go. Lightly flour a surface and roll out the disk to a slab about 1/4-inch thick. Cut out 3 1/2-inch rounds with your cookie cutter and use an offset spatula to transfer the rounds to the sheet pans, leaving about 1 1/2 inches of space between each one. Gather up scraps, re-roll, and cut out any additional rounds.
Working a few at a time, place 1 teaspoon of strawberry IPA jam OR 1 vodka infused gummy peach in the center. Fold sides of each circle up to make a triangle, pinching points gently to seal and leaving about a 1-inch surface of filling exposed. Transfer to the refrigerator to chill while you repeat the process with the second dough disk.
When all the cookies from the second disk have been shaped, transfer to the refrigerator to chill. Remove the first tray and whisk together 1 large egg and 1 teaspoon water in a small bowl. Use a pastry brush to brush the sides of the chilled cookies with the egg wash; sprinkle 1 tablespoon of demerara sugar over the eggs. Transfer to the preheated oven and bake the cookies until golden brown, around 20 to 24 minutes. Transfer to a wire rack to cool completely.
Repeat the egg wash and baking process with the second tray of chilled cookie dough.