Ingredients
1/2 cup (1 stick) cold unsalted butter, cut into small pieces, plus 2 tablespoons melted, plus more for muffin tin and plastic wrap
1/4 ounce active dry yeast
1 cup warm water (105 degrees to 110 degrees)
2 tablespoons sugar
2 cups cake flour, (not self-rising)
2 cups all-purpose flour
1 1/2 teaspoons salt
1 1/2 cups sour cream
2 tablespoons fresh thyme, leaves
Preparation
Lightly butter a standard 12-cup muffin tin, and set aside. Stir together yeast, water, and sugar in a small bowl, and let stand until foamy, about 5 minutes. Stir until yeast dissolves.
Whisk together flours and salt in a large bowl. Using a pastry blender, cut in butter pieces until mixture resembles coarse meal. Stir in yeast mixture. Stir in sour cream and thyme until combined.
Spoon a heaping 1/3 cup dough into each cup of muffin tin. Cover with buttered plastic wrap; let rise in a warm place until doubled in size, about 1 hour.
Preheat oven to 400 degrees. Bake rolls 10 minutes. Remove from oven, and lightly brush with 2 tablespoons melted butter. Bake until golden brown, 16 to 18 minutes. Immediately invert and unmold rolls onto a wire rack. Serve warm.