Preheat your oven to 350°F (175°C) and grease a 9x5 inch loaf pan.

In a medium mixing bowl, cream together ⅓ cup of softened unsalted butter and ¾ cup of sugar until light and fluffy.

Add 2 eggs, 1 tablespoon of key lime zest, 1 tablespoon of key lime juice, and 1 teaspoon of vanilla extract. Mix until combined.

In a separate bowl, whisk together 1½ cups of all-purpose flour, ½ teaspoon of salt, and 1½ teaspoons of baking powder. Gradually add this to the wet mixture alternating with ½ cup of buttermilk.

Pour the batter into the prepared loaf pan and smooth the top.

Bake for about 45 minutes or until a toothpick inserted in the center comes out clean.

To make the glaze, whisk together ¾ cup of powdered sugar and 2 tablespoons of key lime juice until smooth.

Let the bread cool in the pan for about 10 minutes, then transfer it to a wire rack and drizzle the glaze over while still warm.