Preheat the oven to 375 °F (190 °C) and get out a mini muffin pan. In a large mixing bowl, mix together the flour, powdered sugar, cinnamon and salt.
1 1/4 cups (156 grams) flour, 6 tablespoons powdered sugar, 2 teaspoons ground cinnamon, 1/2 teaspoon salt
Add in the vanilla and then cut in the fat using a pastry cutter and then use your hands to combine it until a ball of dough comes together. You can also make this in a food processor.
1 tablespoon vanilla extract, 1/2 cup (113 grams) unsalted butter
Press two teaspoons of dough (13 grams) over the bottom and up the sides of 24 molds of the ungreased mini muffin pan. I think it's easiest to roll it into a ball first and then press in the mold. I used a non-stick pan and the crusts popped out very easily after they were baked. You can use liners if your pan is scratched and you're worried about them coming out in one piece. You could also do a test with just one crust and see if it works well.
Bake for 8 minutes or until very lightly browned (the gluten-free version will be much lighter than in these photos and should have just turned brown) and they feel firm. You don't want them to be too browned or they'll be a little crumbly. Remove the pan from the oven. The middle of the crust may have puffed up a little. Take the back of a 1-teaspoon measuring spoon and flatten the bottom of the crust with it. Let the crusts sit in the pan for 5 minutes (and only 5 minutes!) Then use a knife to wedge them out of the molds and let cool on a wire rack to cool completely, about 20 minutes.
After you take the crusts out of the oven, turn the heat down to 350 °F (167 °C). Place the pecans on a baking sheet and place in the oven for about 5-8 minutes or until they smell toasty. Remove from the oven and let cool while you prepare the filling.