Pusties are a regional favorite here in Central New York State. Very addictive! You can buy special fluted tins to bake these in or use a standard muffin tin. Just make sure to spray the cups with cooking oil to prevent sticking. I guarantee a messy pustie will still be delicious, though!
Make the fillings first, so that they are completely cooled by the time the crusts are ready to go.
Choose the flavor to start with and combine the flour and sugar in a saucepan. Slowly whisk in the eggs and milk until completely incorporated and smooth. Cook until thickened, stirring frequently (add chocolate at this point, stirring until completely melted). Cool, then add the flavoring of your choice. Make certain that the filling is completely cool before filling the crusts.
Preheat oven to 400 degrees F. Spray the cups of a muffin pan or pustie tins with cooking spray and set aside. Mix all crust ingredients in a medium bowl. Do not overwork the dough or it will get tough. Break the dough into two separate rounds. Cover the first with Saran wrap to prevent drying while you roll out the other. Roll out the dough to a 1/4" thickness. Cut with a knife or pizza slicer into 12 (for large muffin tins) or 24 (for mini muffin tins) squares.
Pat bottom crusts into muffin cups, covering the bottoms and sides of each. Roll out the second dough round to 1/4" thickness. Cut into round tops with a biscuit cutter for tops.
Fill the cups with filling. Cover cups with dough tops. Trim off any excess dough. Paint the tops of the pusties with egg wash before baking.
Place in oven for 20 minutes. Let cool for 5 minutes and then remove from tins and let continue to cool right side up.