2 cups all-purpose flour
1/3 cup sugar
1 tbs. baking powder
1/4 teaspoon baking soda
1/2 teaspoon salt
Zest from one large orange (1 tbs., or more if desired)
8 tablespoons unsalted butter, frozen or very cold
1/2 cup sour cream (plus 1 tbs.)
1 large egg
Sliced almonds (optional)
For glaze: 1/2 cup confectioners’ sugar, plus 2 tablespoons
4 teaspoons freshly squeezed orange juice, stirred together
Adjust oven rack to lower-middle position and preheat oven to 400 degrees.
In a medium bowl, mix flour, 1/3 cup sugar, baking powder, baking soda, orange zest, and salt. Add butter and either cut in with fork, or use food processor to pulse a few times (mixture should resemble coarse meal).
In a small bowl, whisk sour cream and egg until smooth.
Using a fork, stir sour cream mixture into flour mixture until large dough clumps form. Use your hands to press the dough against the bowl into a ball. (The dough will be sticky in places, and there may not seem to be enough liquid at first, but as you press, the dough will come together.)
Place on a lightly floured surface and pat into a 7- to 8-inch circle about 3/4-inch thick. Sprinkle with remaining 1 tsp. of sugar. Use a sharp knife to cut into 8 triangles; place on a cookie sheet (preferably lined with parchment paper), about 1 inch apart. Bake until golden, about 15 to 17 minutes. Cool for 15 minutes, and drizzle with glaze. While glaze is still wet, you can sprinkle with more orange zest and sliced almonds.