Follow these easy steps to create your Pumpkin Spice Mini Tarts:

1. Make the Tart Crust: In a large mixing bowl, combine the flour, sugar, and diced butter. Use a pastry cutter or your fingers to mix until the mixture resembles coarse crumbs.
2. Add Egg Yolk: Stir in the egg yolk and enough cold water, one tablespoon at a time, until the mixture forms a dough.
3. Chill the Dough: Shape the dough into a disc, wrap it in plastic wrap, and refrigerate for at least 30 minutes.
4. Preheat the Oven: Preheat your oven to 375°F (190°C).
5. Roll Out the Dough: On a floured surface, roll out the chilled dough to about 1/8 inch thick. Cut out circles to fit your mini tart pans.
6. Fit Dough into Tart Pans: Press the dough circles into the bottoms and sides of the mini tart pans. Prick the bottoms with a fork to prevent bubbling.
7. Pre-bake the Crusts: Bake the tart shells in the preheated oven for 10-12 minutes or until lightly golden. Remove from oven and allow to cool.
8. Prepare the Filling: In a mixing bowl, whisk together the pumpkin puree, sweetened condensed milk, egg, vanilla extract, pumpkin pie spice, cinnamon, and nutmeg until smooth.
9. Fill the Tart Shells: Pour the pumpkin filling into the cooled tart shells, filling them about ¾ full.
10. Bake Again: Return the filled tarts to the oven and bake for an additional 15-20 minutes, or until the filling is set.
11. Cool the Tarts: Remove from the oven and let the mini tarts cool in the pans for about 15 minutes before transferring them to a wire rack.
12. Serve with Whipped Cream: If desired, top each tart with a dollop of whipped cream and a sprinkle of ground cinnamon before serving.

With these simple steps, you’ll create incredible Pumpkin Spice Mini Tarts that are sure to delight!