INGREDIENTS
•
2 cups flour
•
1/4 cup sugar
•
1 1/2 teaspoon cream of tartar
•
3/4 teaspoon baking soda
•
1/4 teaspoon salt
•
1/2 cup chilled butter, cut into 8 slices
•
1/2 teaspoon vanilla extract
•
1/2 cup buttermilk, more as needed
•
3/4 cup blueberries, frozen or partially frozen works best
•
1 Tablespoon milk
•
sugar for sprinkling, if desired