Preheat oven to 425 degrees F. Line a large baking sheet with parchment. In a small bowl, pour hot water over the raisins and let sit 10 minutes, then drain. To a food processor, add raisins, pecans, crystallized ginger, cinnamon and granulated sugar. Pulse until spreadable consistency, adding 1 tablespoon water if the mixture is too thick.

Unroll 1 pie crust. Top the dough with cinnamon-raisin mixture, leaving 1/2-inch rim. With a sharp chef's knife or pizza cutter, cut pie crust round into 16 wedges. Starting from the widest end, roll each wedge up, tucking filling inside. Arrange on prepared baking sheet with tips of dough tucked underneath, spacing cookies 1 inch apart.

In a small bowl, beat the egg with 1 tablespoon water. Brush rugelach tops with the egg wash and, if desired, sprinkle with the turbinado sugar. Bake 22 to 25 minutes, until puffed and golden brown. Store in an airtight container for up to 5 days.