1. Preheat the oven to 350ºF and generously butter an 8x4x2–inch loaf pan (6-cup capacity). In a bowl, whisk together the flour, baking powder, and salt.
2. Whisk the eggs, sugar, sour cream, and vanilla together until well blended. Add the dry ingredients and stir until smooth. Finally, pour in the oil and use the whisk to gently but thoroughly fold it into the batter.
3. Put the batter in the loaf pan and bake 50 to 55 minutes, or until a toothpick inserted in the center of the cake comes out clean. Cool on a rack for 5 minutes, then unmold and cool to room temperature right-side up.
Serves 8. Per serving: 360 calories, 44g carbs, 5g protein, 18g fat, 85mg cholesterol.