How to Make It
Preheat oven to 350°.
Lightly spoon flour into dry measuring cups; level with a knife. Combine the flour, baking soda, and salt, stirring with a whisk.
Place sugar and butter in a large bowl, and beat with a mixer at medium speed until well blended (about 1 minute). Add the eggs, 1 at a time, beating well after each addition. Add banana, yogurt, and vanilla; beat until blended. Add flour mixture; beat at low speed just until moist. Spoon batter into an 8 1/2 x 4 1/2-inch loaf pan coated with cooking spray.
Bake at 350° for 1 hour or until a wooden pick inserted in center comes out clean. Cool 10 minutes in pan on a wire rack; remove from pan. Cool completely on wire rack.
Marble it. Stir 1 cup batter and 1/2 cup melted semisweet chocolate chips together in a small bowl. Spoon plain batter into pan, alternating with dollops of chocolate-chip batter. Drag a knife through batter to swirl. Bake as directed.
Berry it. Fold 1 cup fresh blueberries into batter. Bake as directed.
French-toast it. Cut bread into 3/4-inch slices. Toast until slightly crisp on both sides. Whisk together 2 eggs, 2 Tbsp. milk, ground cinnamon and nutmeg to taste as well as a pinch of salt in a shallow bowl. Dip bread in mixture, let excess drip off, then fry, turning once, in a nonstick skillet lightly coated with vegetable oil over medium-high heat.
Chocolate-chip it. Fold 1 cup dark chocolate chips into batter. Bake as directed.
Streusel it. Combine 2 Tbsp. rolled oats, 2 Tbsp. flour, 1 Tbsp. brown sugar, 1 Tbsp. butter, melted, and 1/4 tsp. ground nutmeg in a medium bowl. Divide batter among 12 paper-lined muffin cups. Top with streusel. Bake at 350°F until done, about 25 minutes.