To make the cakes: Preheat the oven to 350°, and prepare a cake pan with your desired paper liners, set aside.
In a medium bowl, whisk together 1 and ½ c of flour, baking powder, and salt. Set aside.
In the bowl of your stand mixer fitted with the paddle attachment (or in a large bowl with a hand mixer), add the butter and sugar and beat on medium-high speed until creamy, about 2-3 minutes.
Add the eggs, one at a time, mixing well after each addition.
Reduce the mixer speed to low, and alternate adding the flour mixture and the Cherry 7-Up, beginning and ending with the flour, mixing well and scraping down the sides of the bowl as necessary. Add the vanilla and almond extracts, mixing well.
Place about ¾ c of the cake batter in a separate small bowl and add the remaining 1 tbs of flour, maraschino cherry juice, and red food coloring (to your desired tint).
Evenly distribute the red ccake batter among your prepared liners, about 1-2 tsps per liner, gently smoothing out the batter.
Once the red batter is in place, evenly distribute the remaining cake batter among the cake liners, making sure not to mix the two batters.
Bake for 15-20 minutes, or until a cake tester inserted in the middle comes out with a few moist crumbs attached. Let cool completely on a wire rack before frosting.
To make the Buttercream Frosting: cream the butter until light and fluffy, about 2-3 minutes.
Add the pinch of salt, powdered sugar, vanilla and almond extracts, lemon juice, and maraschino cherry juice. Beat for about 2-3 minutes, adjusting texture with more sugar or cherry juice as needed.
Pipe as desired onto your cooled cakes and garnish with a maraschino cherry.