Preheat the oven to 400°F (200°C).

Divide the 1/2 batch of My Favorite Buttermilk Pie Crust into 4 even pieces. If the dough is warm, place all but the piece you are working with in the refrigerator while you shape the first tart.

On a well-floured surface, roll one piece of dough thinly enough that a mini tart pan placed on top would have at least 1 inch of dough around all sides.

Transfer the dough to the tart pan: - If your tart pan has a removable bottom: place the pan bottom (disk) centered on the dough, fold the dough up around the disk so no dough hangs below the disk, set the disk with folded dough into the tart ring, then unfold the dough up the sides of the ring. - If your tart pan does not have a removable bottom: drape the dough over the entire pan and press it into the sides.

Gently press the dough into the sides of the pan, then run a rolling pin lightly over the rim to trim any excess dough. Repeat steps 3–5 for the remaining dough pieces and tart pans. Return any extra dough pieces to the refrigerator as needed.

Set all four tart pans on a baking sheet. Cut four pieces of parchment paper to cover the tart bottoms and place one piece in each tart. Fill the parchment-lined tart shells with pie weights, dry beans, or uncooked rice.

Blind-bake the tart shells at 400°F for 10 minutes.

Remove the parchment and weights, then return the tart shells to the oven and bake 2 to 3 minutes more, until the bottoms look dry and the edges are very slightly golden. If any tart bottom has puffed, gently press it down.

Evenly assemble the tarts on the partially baked shells: spread 1 tablespoon pizza sauce in each tart, divide the shredded mozzarella so each tart gets 2 tablespoons, place 3 slices of pepperoni on each tart, and sprinkle each with 1/2 tablespoon shredded Parmesan.

Place the filled tart pans back on the baking sheet and bake at 400°F for 15 to 20 minutes, until the cheese is bubbly and the crust is golden.

Remove the tarts from the oven and cool in the pans for at least 5 minutes. Top each tart with the thinly sliced pieces of 1 small basil leaf before serving.