In a food processor, pulse the flour and salt together. Then add the cold butter and lard and pulse until the mixture looks like coarse crumbs with some pea-sized pieces. In a small bowl, whisk the egg yolk, vinegar, and ice water, then pour it in while pulsing just until the dough comes together. Shape the dough into a flat disc, wrap it, and refrigerate for 1 hour.

Position an oven rack in the bottom third of the oven and heat it to 450°F. Lightly grease a 12-cup muffin pan with cooking spray.

In a medium bowl, whisk together the brown sugar, corn syrup, maple syrup, eggs, melted butter, vanilla, vinegar, and salt until smooth. If using pecans or raisins, set them aside for later.

On a lightly floured surface, roll the dough to about 1/8 inch thick. Cut out twelve 4 1/2-inch rounds, rerolling the scraps as needed. Gently press each round into a muffin cup and refrigerate the pan for 20 minutes.

Spoon about 2 tablespoons of filling into each shell, adding pecans or raisins if desired. Bake for 8 minutes at 450°F, then reduce the oven to 400°F and bake for about 7 more minutes until the filling is puffed and bubbling and the pastry is golden.

Let the tarts rest in the pan for 3 minutes. Then run a thin knife around the edge of each one, lift them out, and cool completely on a wire rack.