Preheat oven to 350°F.
Whisk egg, corn syrup, sugar, butter and vanilla in a bowl until smooth. Stir in pecans. Set aside.
Unroll pie crusts on counter. Cut out 16 (3 to 3-1/2 inch) circles using a round cookie cutter. A coffee mug or small bowl can also work, carefully cut around with a sharp paring knife or just press like you would a cookie cutter. You will have a little dough left over. Gently fit each circle into muffin cups (2-1/2 inch). Dough should come up about halfway in each cup. Spoon about 1 tablespoon filling into each shell.
Bake for 20 to 25 minutes until filling appears set. Cool 5 to 10 minute on rack. Using a sharp knife, carefully remove each pie from the muffin pan. Store in a tightly closed container.
Recipe Note: Extra pie dough can be cut in pieces, brushed with melted butter and sprinkled with sugar and cinnamon for a warm from the oven treat!