Preheat oven to 350°F (175°C)
Grease a 9×5-inch loaf pan
For each loaf: Mix dry ingredients (flour, baking powder, salt, and any other dry components) in a bowl
In another bowl, cream butter and sugar together until light and fluffy
Beat in eggs one at a time
Add vanilla extract
Alternate adding dry ingredients and wet ingredients (juice, milk, or buttermilk) to the butter mixture, beginning and ending with dry ingredients
For orange loaf: Fold in orange zest and orange juice
For chocolate loaf: Mix cocoa powder with hot water or coffee before adding to batter
For lemon loaf: Fold in lemon zest and lemon juice
For caramel swirl loaf: Pour half the batter into pan, swirl in caramel sauce, top with remaining batter
Bake for 45–55 minutes until a toothpick inserted in the center comes out clean
Cool in pan for 10 minutes, then turn out onto a wire rack to cool completely
Slice and serve
