Make the Pastry:

1. Combine dry ingredients: In a large bowl, mix together the flour, salt, and sugar.

2. Cut in the butter: Add the cold butter cubes to the dry ingredients. Use a pastry cutter or two knives to cut the butter into the flour until the mixture resembles coarse crumbs with some pea-sized pieces of butter still visible.

3. Add ice water: Gradually add the ice water, one tablespoon at a time, mixing with a fork until the dough just begins to come together. You may not need all the water, so add it slowly.

4. Chill the dough: Divide the dough into two equal parts and form each into a disk. Wrap them in plastic wrap and refrigerate for at least 1 hour.

Prepare the Filling:

1. Mix jam and cornstarch: In a small bowl, stir together your choice of jam, cornstarch, and lemon juice until smooth. This will help thicken the jam and keep it from leaking during baking.

2. Add vanilla: If you’re using vanilla extract, stir it in now. Set the filling aside.

Assemble the Mini Pies:

Prep:

1. Preheat the oven: Preheat your oven to 375°F (190°C).

2. Grease the muffin tin: Grease a muffin tin or mini pie pans with butter or non-stick spray.

Roll and Cut:

1. Roll out the dough: Take the first disk of dough from the fridge and roll it out on a floured surface to about ⅛-inch thickness.

2. Cut the dough: Using a 4-inch round cookie cutter or a large glass, cut 12 circles for the bottom crust of each mini pie.

3. Place the dough circles: Press the dough circles gently into the muffin cups, allowing for a slight overhang.

4. Cut tops for the pies: Roll out the second disk of dough and use a 3-inch round cookie cutter to cut 12 smaller circles for the top crust. You can also use small cookie cutters to cut decorative shapes for the tops, such as stars or hearts.

Fill and Seal:

1. Add the filling: Spoon 1-2 tablespoons of the jam mixture into the center of each pastry-lined muffin cup.

2. Place the top crust: Carefully place the smaller dough circles over the jam-filled cups. Gently press the edges to seal, using a fork to crimp the edges.

3. Vent the pies: Use a sharp knife to cut small vents in the tops of the pies to allow steam to escape during baking.