Grease and flour a bundt cake pan or tube pan.
Preheat the oven to 325℉
In a separate bowl, whisk the cake flour, baking powder, and salt to combine, set aside for later.
Using an electric mixer (paddle attachment if using a stand mixer), mix the butter and mascarpone cheese on low to medium speed until combined and smooth.
Next, gradually add the sugar and beat until light and fluffy for three minutes.
Add the eggs to the mixing bowl one at a time, blending after each until the yolk is incorporated.
Combine the ¼ cup of milk, ¼ cup lemon juice, lemon extract, and zest.
With the mixer on low speed, add the flour mixture alternately with the milk to the butter/sugar/egg mixture in the mixing bowl. Begin and end with the dry ingredients. We do three additions of dry ingredients, alternating with two additions of wet. Mix just until incorporated.
Scoop batter into prepared bundt pan.
Bake at 325 degrees for 1 hour and 10 minutes or until a toothpick comes out clean. The top of the cake should spring back when lightly touched when it is done. *Baking times may vary. Depending on the type of pan, etc., you may need additional baking time.
This makes approximately 9.5 cups of batter.
Allow to cool in the pan for 10 minutes before turning out.