Let piecrusts stand according to package directions. Preheat oven to 375°F. In a medium bowl combine apples, toffee pieces, brown sugar, melted butter, and salt; set aside.Advertisement
On a lightly floured surface, unroll one piecrust at a time. Using a 3-inch round cookie cutter, cut pastry into 24 circles, rerolling scraps as necessary. Press pastry circles onto the bottoms and up the sides of 24 ungreased 1-3/4-inch muffin cups. Spoon about 1 tablespoon of the apple mixture into each cup.
Bake about 18 minutes or until pastry is golden and filling is bubbly. Remove tartlets from muffin cups and cool on a wire rack. If desired, sprinkle with powdered sugar.
Layer tartlets between sheets of waxed paper in an airtight container; cover. Store in the refrigerator for up to 3 days or freeze for up to 3 months.