Step 1

Cube the 2 sticks of unsalted butter and measure out the buttermilk then freeze both for 10 minutes.

Step 2

In a large bowl, combine the flour, sugar, and salt, fluffing with a fork to aerate. Add the cold butter and cut it into the flour mixture with a pastry cutter or your fingers until the butter is about the size of peas. This can also be done in a food processor but be very judicious.

Step 3

Pour in 1/2 cup of buttermilk, the vinegar if using, and stir with a fork until it starts to come together. It will be quite loose. Grab a small amount of the mixture and pinch it together; if it doesn’t hold together, add a tablespoon more buttermilk and stir. Repeat until the dough holds together lightly but enough.

Step 4

Lightly flour a work surface and dump the crust dough out onto it. Push the dough together and knead a couple times until it forms into mostly a ball then cut it in half. Wrap each half in plastic wrap and form the dough into disks then chill in the refrigerator for at minimum 1 hour, up to 3 days.