Part 1: Make the Cherry Reduction (Can be done a day ahead)

1. Combine Ingredients: In a small saucepan, combine the pitted cherries, granulated sugar, and lemon juice.

2. Simmer and Reduce: Place the saucepan over medium heat and bring to a simmer, stirring occasionally. As the cherries cook, mash them gently with the back of a spoon or a potato masher to release their juices.

3. Thicken: Continue to simmer for 15-20 minutes, or until the cherries have broken down and the liquid has reduced and thickened into a syrupy consistency.

4. Strain (Optional): For a completely smooth reduction for the frosting, you can press the mixture through a fine-mesh sieve, discarding the solids. For a more rustic frosting with small bits of fruit, you can skip this.

5. Cool Completely: Transfer the reduction to a small bowl and let it cool completely to room temperature. You can speed this up by placing it in the refrigerator. It must be completely cool before using in the frosting. This step is critical.

Part 2: Make the Vanilla Cherry Cakes

1. Preheat and Prepare Pans: Preheat your oven to 350°F (175°C). Grease and flour three 8-inch round cake pans. For extra security, line the bottoms with parchment paper, then grease the parchment paper as well.

2. Whisk Dry Ingredients: In a medium bowl, whisk together the sifted cake flour, baking powder, baking soda, and salt. Set aside.

3. Cream Butter and Sugar: In the bowl of a stand mixer fitted with the paddle attachment, or in a large bowl with a hand mixer, beat the softened butter and granulated sugar together on medium-high speed for 3-4 minutes, until very light, pale, and fluffy. This step incorporates air and is key to a light cake.

4. Add Eggs and Vanilla: Add the room temperature eggs one at a time, beating well after each addition and scraping down the sides of the bowl as needed. Beat in the vanilla extract.

5. Alternate Wet and Dry Ingredients: Reduce the mixer speed to low. Add the dry ingredients in three additions, alternating with the buttermilk in two additions, beginning and ending with the dry ingredients. (Dry, Wet, Dry, Wet, Dry). Mix only until just combined after each addition. Do not overmix.

6. Divide and Swirl: Divide the batter evenly among the three prepared cake pans. Dollop about 1 tablespoon of the cooled cherry reduction onto the batter in each pan. Use a skewer or a butter knife to gently swirl the reduction into the batter a few times to create ribbons. Do not overmix.

7. Bake: Bake for 25-30 minutes, or until a wooden skewer inserted into the center of the cakes comes out clean or with a few moist crumbs attached.

8. Cool: Let the cakes cool in their pans on a wire rack for 15 minutes before inverting them onto the rack to cool completely.

Part 3: Make the Cherry Buttercream and Assemble the Cake

1. Beat the Butter: In a large bowl with an electric mixer, beat the softened butter on medium speed until it is smooth and creamy, about 2 minutes.

2. Add Sugar and Liquid: Add 4 cups of the sifted powdered sugar, the cooled ¼ cup of cherry reduction, the vanilla extract, and 2 tablespoons of heavy cream. Beat on low speed until the sugar is incorporated, then increase the speed to medium-high and beat for 3-5 minutes until light, fluffy, and smooth.

3. Adjust Consistency: If the frosting is too stiff, add more heavy cream, one tablespoon at a time. If it’s too thin, add more powdered sugar, ¼ cup at a time. Add a pinch of salt to balance the sweetness.

4. Assemble the Cake: Place one cake layer on your serving plate or cake stand. Top with about ¾ to 1 cup of frosting, spreading it evenly. Place the second cake layer on top and repeat. Place the final cake layer on top.

5. The Crumb Coat: Apply a very thin layer of frosting over the top and sides of the entire cake. This layer traps any loose crumbs. Refrigerate the cake for 20-30 minutes until the crumb coat is firm to the touch.

6. Final Frosting: Cover the entire cake with the remaining frosting, using an offset spatula to create a smooth or textured finish as you desire. Garnish with fresh cherries.