Step 1

Make the crust: In a food processor fitted with the metal blade, add the flour, salt, and sugar. Pulse briefly to combine. Add the cold butter and process just until you have pea-size clumps of butter, about 8 seconds. Sprinkle the cold water over the mixture and process just until moistened and clumpy, about 8 seconds. Transfer the dough to a lightly floured work surface and knead a few times, just until it comes together into a cohesive ball. Pat and knead the dough into a 6-inch disk, flouring and turning the dough as necessary so it doesn’t stick. Wrap the dough in plastic wrap and refrigerate for at least 30 minutes or up to 3 days.

Step 2

Preheat the oven to 375°F and set an oven rack in the middle position.

Step 3

Take the dough from the fridge and unwrap onto a lightly floured work surface. (If it's been in the fridge for longer than 30 minutes, you may need to knead it just a bit until it's malleable enough to roll.) Roll the dough to about ⅛ inch thick, flouring and turning as necessary so it doesn't stick. Don't worry about the shape. Using a 4-inch-diameter cookie or biscuit cutter, cut the dough into as many circles as possible. Line each cup of an ungreased standard 12-cup muffin pan with one of the circles, gently nudging it down into the bottom creases of the pan. The top edge of the dough circle should come all the way up to the top of the cup. Gather the scraps and reroll the dough if you need additional ­circles. Chill the pan in the freezer while you prepare the filling.

Step 4

Make the Filling: In a medium bowl (preferably with a pouring spout), whisk together the brown sugar, maple syrup, butter, egg, vinegar, vanilla, and salt.

Step 5

Divide the pecans and raisins (if using), among the pastry-lined muffin cups. Pour the filling evenly into the muffin cups. Bake for about 25 minutes, until the tarts are golden brown, bubbling, and set. Let cool on a wire rack for a few minutes, then run a butter knife around the edge of each tart to loosen. Let the tarts cool completely in the pan, then remove. Serve at room temperature.

Step 6

Note: Nutritional information does not include the optional raisins.

Step 7

Make-Ahead/Freezing Instructions: The butter tarts will keep at room temperature for up to 3 days. Once cooled, store them in an airtight container, using parchment paper between layers. To extend freshness, you can freeze the cooled tarts in the same manner. When ready to enjoy, thaw at room temperature. For unbaked tarts, freeze them on a baking sheet until solid, then transfer to an airtight container. To bake from frozen, simply add a few extra minutes to the original baking time.