2 1/2 cups sifted all purpose flour
1/2 cup (1 stick) chilled unsalted butter, diced
1/3 cup sugar
2 tablespoons sugar
1 tablespoon plus 1 teaspoon baking powder
1/2 teaspoon cream of tartar
1/4 teaspoon salt
3/4 cup chilled whipping cream

Position rack in center of oven and preheat to 375°F. Line large cookie sheet with parchment paper.  Generously butter parchment.

In a food process, place first 7 ingredients in work bowl.  Process until mixture resembles coarse meal.  Remove cover and pour cream evenly over mixture.  Using on/off turns, process just until dough forms moist clumps.

Transfer dough to lightly floured work surface.  Knead gently just until dough holds together.  Pat out to thickness of 1 inch.  Cut into 3-inch rounds using floured biscuit cutter or glass.  Gather scraps and pat out to thickness of 1 inch.  Cut out additional rounds.  Transfer biscuits to prepared cookie sheet, spacing 3 inches apart Bake until light brown, about 18 minutes (biscuits will spread).  Transfer to rack.  Cool to just warm, about 15 minutes.