Preheat your oven to 325°F (163°C). This ensures even baking and a perfect golden brown color.
Grease and flour your 9x5 inch loaf pan. Alternatively, use parchment paper for easier removal.
In a stand mixer, cream together the unsalted butter and granulated sugar until light and fluffy, about 5 minutes.
Add the eggs one at a time, mixing well after each addition to ensure a smooth batter.
In a separate bowl, whisk together the sifted cake flour and salt to evenly distribute the salt.
Gradually add the dry ingredients to the butter mixture, alternating with the 7UP soda. Start and end with the flour mixture, mixing just until combined to keep the cake tender.
Stir in the lemon extract to add a refreshing citrus flavor.
Pour the batter into the prepared loaf pan, smoothing the top with a spatula for even rising.
Bake for about 60-70 minutes or until a toothpick inserted in the center comes out clean. Watch carefully near the end to prevent overbaking.
Let the cake cool in the pan for about 10 minutes, then transfer to a cooling rack. For the glaze, whisk together the confectioners sugar, 3 tablespoons of 7UP, and 1 teaspoon of lemon extract until smooth and drizzle over the cooled cake.