Step 1: Prepare The Crust

In a mixing bowl, combine the flour, salt, and sugar. Add some butter which is cold then cut it into the floor using some pastry cutter or fingers until it looks like coarse crumbs.

Gradually add cold water, 1 tablespoon at a time, mixing gently until the dough comes together.

Shape the dough into a disk, wrap it in plastic, and refrigerate for 15 minutes.

Step 2: Make The Filling

In a medium bowl, whisk together the brown sugar, maple syrup, melted butter, egg, vinegar, vanilla extract, and salt until smooth.

If using raisins or pecans, stir them into the mixture.

Step 3: Assemble The Tarts

Preheat your oven to 375°F (190°C) and grease a 12-cup muffin tin.

Roll out the dough on a floured surface to about ⅛-inch thickness. Use a 4-inch-diameter cookie cutter to cut out 12 circles.

Gently press each dough circle into the muffin cups, ensuring they reach the edges.

Step 4: Fill And Bake

Spoon the filling into each pastry shell, filling about two-thirds full.

Bake on the middle oven rack for 18–20 minutes, or until the filling is set and the crust is golden.

Let the tarts cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely.