Preheat oven to 350 degrees. Grease a loaf pan and line with parchment paper.

In the bowl of a stand mixer cream together ¾ cup of butter and 1½ cups sugar until light and fluffy. Add eggs, one at a time, beating well between each addition.

Mix in vanilla extract and lemon zest.

Turn mixer to a slow speed and add flour a little bit at a time. Add salt.

Once the flour is fully incorporated, slowly pour in the 7UP. Mix until well combined.

In a small pan melt remaining 2 tablespoons of butter. Whisk in brown sugar until sugar melts and a smooth mixture forms. Pour into the bottom of the prepared loaf pan.

Cover the brown sugar mixture with an even layer of lemon slices being careful to remove any seeds. When the bottom of the pan is completely covered, top with batter.

Bake for 50-60 minutes or until a toothpick inserted comes out clean. Allow to cool in the pan for 10-15 minutes before carefully turning out onto a cooling rack.