If using frozen cherries, allow to thaw slightly before cooking. In a saucepan, combine the cherries, sugar, brandy, and lemon juice. Bring to a simmer over medium high heat. Cook the cherries for about 5 minutes, or until they begin to breakdown. You can lightly mash the cherries with a potato masher if desired. Add the almond extract.
In a small cup, stir together the cornstarch and water until dissolved. Add to the cherries, stirring quickly to prevent clumping. Bring to a boil and cook until thick. Remove from the heat and transfer to a bowl. Cover with a piece of cling film placed directly onto the filling and chill.
Almond Cake
Preheat the oven to 350° F. In the bowl of a stand mixer fitted with a paddle attachment, combine the softened butter and sugar. Beat on low for a minute just to combine the butter and sugar. Scrape down the sides and turn the speed up to medium high. Beat for 2 to 3 minutes or until the butter is lightened in colour and fluffy.
Turn the mixer down to low and add the almond extract along with one egg. Mix until the egg is fully incorporated, scraping down the sides as needed. Add the remaining eggs, one at a time, beating until fully combined. Once all the eggs have been added, turn up the speed to medium and beat for another minute until the mixture is thick, fluffy, and fully emulsified. Turn off the mixer.
Meanwhile, in a separate bowl, combine the flour, almond flour, baking powder, baking soda, and salt. Whisk together until there are no lumps, then set aside. Add the vegetable oil to the buttermilk and whisk to combine.
Turn the mixer back on low. Add one third of the flour mixture and mix just until the flour is mostly incorporated. Pour in half the buttermilk mixture and continue beating until it is mostly incorporated. Stop the mixer and scrape down the sides. Repeat by adding another third of the flour followed by the remainder of the buttermilk. Add the last of the flour and mix on low just until the batter is fully combined.
Use a spatula to scrape down the sides of the mixing bowl and make sure there are no streaks of unmixed butter in the batter. Line three 6" or 7" cake pans with parchment paper.* Spray with non-stick spray and lightly flour the pans.
Divide the cake batter between the pans and smooth the tops. Bake for 30 to 35 minutes until a toothpick comes out clean and the top springs back when touched. Let the cakes cool for 5 minutes then turn out onto a rack to cool completely.
Almond Buttercream
In a stand mixer fitted with a paddle attachment, whip the softened butter. Beat the butter for about 10 minutes until it's lightened in colour and fluffy. Add the icing sugar and mix just until combined. Add the heavy cream, almond extract, and food colouring. Beat until the buttercream is smooth. Check the consistency, adding a bit more cream as needed.
To Assemble
If the cake layers have domed tops, use a serrated knife to level them off. Place one layer on a serving platter or cake board. Top with a thin layer of buttercream. Fill a piping bag fitted with a star tip with some of the buttercream.
Pipe a ring of buttercream around the edge of the cake layer to create a well. Fill the well with some of the cherry filling, smoothing the top. Cover with a second cake layer. Repeat the filling. If the cake feels unsteady, refrigerate for 15 to 20 minutes to set the buttercream.
Frost the outside of the cake and pipe decorative borders around the top and bottom. Pipe a ring of rosettes around the top of the cake. Top each rosette with a maraschino cherry. Store the cake in the fridge. Be sure to remove it from the fridge a couple of hours before serving to soften the buttercream. Enjoy!