In a medium bowl, whisk together the cake flour, baking powder, salt, and baking soda. Set aside.

In a separate large mixing bowl, cream together the softened butter, oil, and sugar on medium speed until light and fluffy. Add the eggs one at a time, beating well after each addition. Mix in the almond, lemon extracts and sour cream.

Add the dry ingredients in and mix until just combined, making sure to scrape the bottom of the bowl and the sides of the bowl.

In a microwave safe measuring cup heat up the milk until hot, and then pour it into the creamed cake batter and mix

Divide the batter evenly among the prepared cake pans. . Bake in the preheated oven for 20-25 minutes, or until a toothpick inserted into the center comes out clean. Allow the cakes to cool in the pans for 10 minutes before transferring to wire racks to cool completely.

While the cakes are cooling, prepare your the almond filling and frosting.

Once the filling has fully cooled, break it apart and place it into a medium sized bowl. Add all the mascarpone to the filling and mix everything together until it combines. It should be smooth and creamy.

In your stand mixer add the room temperature cream cheese and unsalted butter and whip on medium speed until smooth. Make sure to scrape the bottom and sides of the bowl with a rubber spatula.

Add in the powder sugar 1 cup at a time mixing on low. Scrape the sides of the bowl every so often to have a smooth and silky frosting. Add in the lemon juice and lemon extract  and mix until just combined. If the frosting is too soft place the bowl in the fridge for 15 to 25 minutes until it's easier to work with.

Once the cakes are completely cooled, place one layer on a serving dish. Spread a thin layer of frosting on top and then fill a piping bag with the cream cheese buttercream and fill the inside with the almond mascarpone filling. Repeat with the remaining layers, stacking them on top of each other and the remaining frosting and almond filling.