Preheat your oven to 350°F (175°C) and grease a 9×5-inch loaf pan or line it with parchment paper for easy removal.

In a large mixing bowl, cream together the softened butter and granulated sugar until the mixture is light and fluffy—this usually takes about 3-4 minutes.

Add the eggs one at a time, mixing well after each addition to ensure they’re fully incorporated into the mixture.

In another bowl, whisk together the flour, baking powder, baking soda, and salt.

Gradually add the dry ingredients to the wet mixture, alternating with the key lime juice. Make sure to mix well after each addition.

Once combined, gently fold in the key lime zest and vanilla extract. Be careful not to overmix!

Pour the batter into the prepared loaf pan and smooth the top with a spatula.

Bake in the preheated oven for 60-70 minutes, or until a toothpick inserted into the center comes out clean.

Once baked, let it cool in the pan for about 10 minutes, then transfer it to a wire rack to cool completely before slicing.