Angel Biscuits

Combine warm water and yeast in a small bowl. Let stand until foamy, about 5 minutes.

Meanwhile, combine all-purpose flour, whole-wheat flour, baking powder, baking soda and salt in a large bowl. Using a pastry cutter or 2 knives, cut butter into the dry ingredients until the mixture resembles coarse meal. Add buttermilk and the yeast mixture and stir to combine. The dough will appear uneven in moisture and dry in spots.

Turn the dough out onto a lightly floured surface. Knead lightly, using the heel of your hand to compress and push the dough away from you and then fold it back over itself. Turn the dough 90 degrees and knead again. Repeat turning and kneading 4 more times. Shape into a rectangle.

Cut the rectangle into 4 pieces and stack them on top of each other. Roll out again to a rectangle about 1 inch thick. (If desired, refrigerate the dough airtight for up to 2 days.)

Line a baking sheet with a silicone baking mat or parchment paper. (If using chilled dough, knead it about 10 times on a lightly floured surface to punch it down, then roll to about 1 inch thick.) Using a 2 1/2-inch round cutter, cut out the biscuits as close together as possible. Gather and stack the scraps. Knead until a cohesive dough forms again and roll it out once more. Stamp out as many biscuits as possible and discard the remaining scraps.

Place the biscuits on the prepared baking sheet. Cover loosely with plastic wrap or a clean kitchen towel and set aside to rise in a warm place for about 30 minutes. Meanwhile, preheat oven to 425°F.

Bake the biscuits until golden brown, 10 to 15 minutes. Transfer to a wire rack to cool slightly. Serve warm.