Roll dough flat and cut to make a large square or rectangle. A pizza cutter is ideal for this. Roll the second pie crust out on a piece of parchment or wax paper (don't cut it yet).
Mix pumpkin, egg, cinnamon, and allspice until well combined.
Spoon the filling onto the pie crust that you cut. Spread it evenly with the back of the spoon or spatula.
Carefully flip the second pie crust onto the first one. Press lightly on the top starting at the center and working your way out. Remove any air pockets that have formed.
Cut the top crust to match the bottom crust. Pinch the edges with a fork to seal in the filling.
Brush with melted butter.
Place on a cookie sheet and bake at 375 degrees 22 to 25 minutes or until lightly brown.
BROWN BUTTER GLAZE
Heat butter in a saucepan over medium heat. Whisk until golden brown, usually 8 to 10 minutes. Carefully pour the butter into a bowl, leaving sediment behind. You can pour it through a strainer.
Add sugar, vanilla, and 2 tablespoons of heavy cream to the butter. Stir until smooth. You can add more heavy cream if the glaze is too thick. Pour it over the pop tart immediately. It will begin to harden as the butter cools.
Notes
For a change, you can add 1/2 cup ricotta cheese over the pumpkin before you put the top crust on.