Preheat the oven to 350°F (175°C).

Grease a 9x13 inch baking pan with butter or cooking spray.

In a mixing bowl, whisk together the flour, baking soda, and salt.

In another bowl, cream the softened butter and sugar together until light and fluffy.

Beat in the eggs, vanilla extract, and lemon extract until fully combined.

Add the dry ingredients to the butter mixture, alternating with the 7 Up soda.

Pour the batter into the prepared baking pan and spread it evenly.

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

Let the cake cool in the pan for about 10 minutes before transferring it to a cooling rack.