Preheat oven to 350 degrees F. Spray the bottoms and sides of the mini muffin tins with cooking spray.
For the dough:
In a food processor, pulse the pecans, sugar, salt, and flour, until the nuts are ground and the ingredients are combined. Add in the butter and pulse until dough resembles coarse meal. Slowly pour in the ice water through the feed tube until the dough comes together. Remove from processor bowl to a clean work surface sprinkled with flour. Form the dough into a ball and divide evenly into 24 pieces. Roll each piece into a ball and evenly press into each cup, until the bottom is covered. If the dough is sticky, dip your finger in flour first. Bake until the crusts are very golden, 15 to 18 minutes, until the crusts are very golden. Check periodically to make sure they don't get too brown. Meanwhile, make the filling: In a medium bowl, whisk the egg yolk, corn syrup, sugar, pumpkin filling and vanilla. Stir in the chopped pecans. Remove the dough from the oven and spoon 1 tablespoon of the filling into each cup. Top each with 1 pretty pecan half. Return the pans to the oven and continue baking, for 12 to 15 minutes more, until the pumpkin filling is set. Allow to cool before removing from the pans.