2 cups (250g) all-purpose flour, plus extra for rolling
2 tablespoons brown sugar
1/2 teaspoon salt
1/2 cup (115g) cold shortening, cut into small pieces
1/4 cup (57g) cold butter, cut into small pieces
4–6 tablespoons ice water
For the Filling:
1/2 cup (115g) butter, melted and slightly cooled
1 cup (220g) packed brown sugar
2 large eggs, at room temperature
2 tablespoons corn syrup
1 tablespoon vanilla extract
Pinch of salt
Optional Mix-ins:
3/4 cup raisins, or chopped pecans, or chopped walnuts, or 1/2 cup chocolate chips
Instructions
Make Pastry: Whisk flour, brown sugar, and salt in a large bowl. Cut in cold shortening and butter until mixture resembles coarse crumbs. Add ice water one tablespoon at a time until dough comes together. Form into a disk, wrap, and chill for 30 minutes.
Prepare Tins: Preheat oven to 375°F (190°C). Lightly grease a 12-cup muffin tin.
Roll and Line: Roll chilled dough to 1/8 inch thickness. Cut 12 circles and press into muffin cups.
Make Filling: Whisk melted butter and brown sugar. Add eggs one at a time, then stir in corn syrup, vanilla, and salt until smooth.
Fill Tarts: Divide mix-ins among pastry cups if using. Pour filling over mix-ins, filling each cup two-thirds full.
Bake: Bake 15-18 minutes until filling is set with a slight jiggle in the center. Pastry edges should be lightly golden.
Cool: Let cool in pan for 10 minutes, then transfer to a wire rack to cool completely.