Preheat the oven to 350°F. Grease 16 cups of two standard muffin tins or line with paper liners.
Whisk together in a large bowl:
Beat in another bowl:
Add the buttermilk mixture to the flour mixture and combine with a few swift strokes. Fold in, before the dry ingredients are entirely moist:
Divide the batter among the muffin cups. Bake until a toothpick inserted in 1 or 2 of the muffins comes out clean, about 25 minutes. Let cool for 2 to 3 minutes in the pans. If not serving hot, transfer the muffins to a wire rack to cool. Serve within a few hours of baking.