Preheat and Prep: Preheat your oven to 350°F. Mix the milk with the lemon juice and let it sit for 10 minutes to curdle.
Creaming: In the bowl of a food processor, cream together the butter and sugar until light and fluffy. Add the eggs one at a time, beating well after each addition.
Combine Dry Ingredients: Gradually add the flour, baking powder, baking soda, and vanilla, mixing until just combined.
Add Milk: Slowly pour in the curdled milk, mixing until the batter is smooth.
Bake: Grease three 6-inch (15 cm) springform pans. Divide the batter evenly among the pans and bake for 30 minutes, or until a toothpick inserted into the center comes out clean.