Preheat your oven to 315°F. Prepare a 10-cup Bundt pan with the nonstick method of your choice (I used vegetable shortening and flour).
In the bowl of your stand mixer fitted with the whisk attachment, beat the butter for 2 minutes on high speed.Slowly add the sugar and salt. Cream together for an additional 7 minutes until very pale yellow and fluffy.
Add the eggs 1 at a time, combining well after each addition and scraping down the sides and bottom of the bowl as needed.
Turn your mixer down to its lowest speed and slowly add the flour in 2 batches. Be careful not to over beat. Pour in the 7UP and lemon extract. Scrape down the sides and bottom of the bowl and mix the batter until just combined. Be careful not to overmix.
Pour the batter into the prepared pan and bake for 75-85 minutes, or until a toothpick inserted into the center of the cake comes out clean. Let the cake cool in the pan on a wire rack for 10 minutes, then invert onto a serving plate. Let cool to room temperature. Lightly cover the cake with foil or plastic wrap so it doesn't dry out.
Adapted from Jocelyn Delk Adams