In a large mixing bowl, combine the flour, sugar, and salt. Incorporate the cold butter using a pastry cutter or your fingers until the mixture achieves a crumbly texture, with the butter in pea-sized chunks. Alternatively, use a food processor to combine the flour, salt, and sugar, then add the butter and pulse until crumbly.

Gradually mix in 2-3 tablespoons of cold water, handling the dough until it forms a cohesive ball. Add more ice water if necessary. In a food processor, add water and pulse until the dough starts to form a ball.

Shape the dough into a thick disk and wrap it in plastic wrap. Refrigerate for a minimum of 1 hour or up to a week.

Roll out the pastry on a large piece of wax paper to a suitable thickness.

Use a circular cookie cutter, a large cup, or a small bowl to cut the dough into rounds of 3.5-4 inches in diameter.

Place the rounds into a 12-cup muffin pan, gently pressing them into the bottom and up the sides of each cup. If any holes appear, repair them by pressing the pastry together. Then, freeze the pan for 10-15 minutes.

Preheat the oven to 350 degrees Fahrenheit (175 degrees Celsius).

In a large bowl, whisk together the brown sugar, corn syrup, melted butter, eggs, vinegar (if using), and vanilla extract.

Carefully distribute the filling into the unbaked tart shells, filling each one evenly.

Bake in the preheated oven for 20-25 minutes, or until the pastry is golden brown and the filling has slightly puffed.

Allow the tarts to cool in the pan for 10 minutes before transferring them to a wire cooling rack.

Store the baked butter tarts in a refrigerator for several days or freeze them for up to 3 months.