Prepare the Loaf Pans:

1. Preheat the Oven: Set the oven to 350°F (175°C). Grease or line 6 mini loaf pans with parchment paper for easy removal of the cakes.

Make the Cake Batter:

2. Combine Dry Ingredients: In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt. Set aside.
3. Cream Butter and Sugar: In a large bowl, beat the softened butter and granulated sugar until light and fluffy, about 2-3 minutes.
4. Add the Eggs: Beat in the eggs one at a time, ensuring each is fully incorporated before adding the next.
5. Add the Sour Cream, Lime Juice, and Zest: Stir in the sour cream, key lime juice, lime zest, and vanilla extract until well combined.

Combine and Bake:

6. Add the Dry Ingredients: Gradually fold in the dry ingredients until just combined. Be careful not to overmix.
7. Pour into Pans: Divide the batter evenly among the prepared mini loaf pans, filling each about 2/3 full.
8. Bake: Bake for 40-45 minutes or until a toothpick inserted into the center of the cakes comes out clean. If the tops start to brown too quickly, tent the pans with aluminum foil.

Make the Glaze:

9. Prepare the Glaze: While the cakes bake, prepare the glaze by mixing the softened cream cheese, powdered sugar, and key lime juice in a small bowl. Add heavy cream for a smoother consistency if needed.

Cool and Glaze the Cakes:

10. Cool the Cakes: Allow the mini loaves to cool in the pans for 10 minutes before transferring them to a wire rack to cool completely.
11. Drizzle the Glaze: Once the cakes have cooled, drizzle the cream cheese glaze over the top of each loaf.