You can mix this by hand. Or you can blitz it real quick in a food processor. I love my Cuisinart Food Processor.
Sour Cream Pie Crust
3 3/4 cups all-purpose flour
1 T. sugar
1/2 tsp. salt
1/2 tsp. baking powder
1 3/4 cups cold unsalted butter, cut up
2/3 cups ice cold water
2 T. sour cream
1 tsp. vinegar
In a very large bowl combine flour, sugar, salt and baking powder. Cut in butter leaving pea sized chunks.
In a 2 cup glass measuring cup whisk water, sour cream, and vinegar; pour, all at once into flour mixture, and quickly distribute then Stop!! (that's what it says...Stop!)
Make sure dough is slightly crumbly. Divide dough mixture into 3 equal portions (about 12-13 oz. each). Refrigerate for 2 hours. (You can keep it in the fridge over night if you like.) DO NOT OVERMIX. You're going to finish the dough by hand. The finished dough should break, not stretch.
Gently knead the dough in a bag to bring dough together. Form into discs. (This makes three single pie crusts.)
Use at once or wrap and store in the fridge for a few days or freeze for up to 1 month. Thaw overnight in the fridge if you froze it.