Preheat your oven to 350°F. Spray each cavity of a standard 12-cup muffin tin generously with nonstick cooking spray. Optional: Add small strips of parchment paper across the bottom of each cup, letting the ends stick up like handles for easier removal.
Unroll your first pie crust onto a lightly floured surface. Roll it out gently until it forms a 12-inch circle, about 1/8-inch thick.
Using a 3-inch round cookie cutter, cut out 12 circles from the pie dough, positioning them as close together as possible. Repeat with the second pie crust. Gather leftover scraps, reroll gently, and cut additional circles for a total of 24 crusts.
Gently press each dough circle into a muffin cup. Use your fingers to shape it snugly against the bottom and sides. The dough should come about halfway up the sides of each cup. Check for tears or holes.
In a large mixing bowl, combine the brown sugar, melted butter, and corn syrup. Whisk vigorously until the mixture becomes smooth and the sugar begins to dissolve.
Add the vanilla extract, cinnamon, and salt. Whisk again until the mixture looks glossy. Fold in the chopped pecans, stirring until every piece is coated.
Add the lightly beaten eggs. Stir gently but thoroughly until everything combines into a uniform mixture. Don't overmix.
Using a spoon or small ladle, carefully fill each prepared crust about two-thirds full (approximately 1 1/2 tablespoons of filling per cup). Don't overfill.
Bake for 18-22 minutes until the crust edges turn golden brown and the filling is set around the edges but still slightly jiggly in the very center.
Remove from the oven and let cool in the pan for at least 10 minutes. The filling continues to set during this time. After 10 minutes, carefully transfer to a wire rack to cool completely.
Serve at room temperature or slightly warm. Top with whipped cream, vanilla ice cream, caramel sauce, or flaky sea salt if desired.