Preheat your oven to 350°F (175°C). Grease and flour your loaf pans ahead of time.
In a medium bowl, whisk together the all-purpose flour, baking powder, and salt.
In a large mixing bowl, beat the unsalted butter and Crisco shortening together until light and fluffy (about 3-5 minutes).
Gradually add the sugar to the creamed mixture, continuing to beat until pale and fluffy.
Add in the eggs, one at a time, mixing well after each addition.
Mix in the whole milk, lemon juice, and lemon zest.
Slowly add the dry ingredient mixture to the wet ingredients, mixing until just combined.
Divide the batter evenly between the prepared loaf pans and smooth the tops.
Bake in the preheated oven for 60-75 minutes, or until a toothpick comes out clean.
Once baked, let the cakes cool in the pans for about 10 minutes, then transfer to a cooling rack.
