Prepare a muffin tin with white cupcake liners. I used the white ones so the colors of the cake will show through after they're baked.
In a mixing bowl whisk together the flour, baking powder and salt. Set aside.
Add the slivered almonds to the bowl of a food processor. Process until finely ground, about 1 minute. Set aside.
In a stand mixer fitted with the paddle attachment beat the butter, sugar and almond extract on medium/high speed until light and fluffy, about 5 minutes. Scrape down the sides of the bowl and with the mixer on low speed add in the eggs one at a time waiting until each one is fully incorporated before adding the next.
Add in the sour cream and ground almonds and mix until fully incorporated. Alternate adding in the dry ingredients with the milk ending with the dry ingredients.
Scoop out 1/3 of the batter and add it to a mixing bowl. Color the batter with a mixture of red and yellow food coloring until the desired shade of orange is reached (I had to use quite a bit of food coloring to get my batter a nice orange color).
Color the remaining batter with yellow food coloring as desired.
Using an ice cream scoop add a full scoop of yellow batter to each of the paper liners. Add about 2 tablespoons of the orange batter on top of the yellow batter and smooth the tops with a spoon. Bake for 18-20 minutes or until an inserted toothpick comes out clean. Cool completely before frosting.
To make the Frosting::
In the bowl of a stand mixer fitted with a paddle attachment beat together the cream cheese, butter and sugar until combined. Fold in the mascarpone very gently (mascarpone can be delicate and has a tendency to curdle if you're not careful!)