Preheat the oven to 350°F (180°C). Spray 2 (8-inch) round cake pans with baking spray with flour.

For vanilla layers: In the bowl of a stand mixer fitted with the paddle attachment, whisk together flour, granulated sugar, baking powder, baking soda, and salt by hand. Add butter, and beat on medium-low speed until well combined and mixture resembles sand, 1 to 2 minutes.

In a medium bowl, whisk together eggs, milk, oil, sour cream, and vanilla paste. Add to flour mixture, and beat on medium speed until smooth and fluffy, about 2 minutes, stopping to scrape paddle and bottom and sides of bowl.

Divide batter between the prepared pans (about 3 cups or 589 grams each), and tap the pans on the counter to release any trapped air bubbles.

Bake until a wooden pick inserted in the center comes out clean, 30 to 35 minutes. Allow the cakes to cool in the pans for 5 minutes and then turn over onto a wire rack to cool completely. Leave oven on.

Clean mixer bowl and paddle attachment; re-attach to stand mixer. Clean and dry cake pans; spray with baking spray with flour.

For red velvet layers: In the bowl of a stand mixer fitted with the paddle attachment, whisk together flour, granulated sugar, cocoa, baking powder, baking soda, and salt by hand. Add butter and oil, and beat on medium-low speed until well combined and mixture resembles sand, 1 to 2 minutes.

In a medium bowl, whisk together eggs, sour cream, food coloring, vanilla paste, and vinegar. Add to flour mixture, and beat on medium speed until smooth and fluffy, about 2 minutes, stopping to scrape paddle and bottom and sides of bowl.

Divide the batter between the prepared pans (about 3 cups or 589 grams).

Bake until a wooden pick inserted in the center comes out clean, 28 to 32 minutes. Allow the cakes to cool in the pan for 5 minutes and then turn over onto a wire rack to cool completely.

For chocolate ganache: While the cakes are cooling, make the ganache. Add chocolate and heavy cream to a microwave-safe bowl. Heat on high in 15-second increments, stirring between each, until chocolate is melted and mixture is smooth and well combined. Place in the refrigerator to set, at least 1 hour and 30 minutes.

For cream cheese frosting: Add butter to the bowl of a stand mixer fitted with the paddle attachment. Beat for 2 minutes on medium speed and then add cream cheese, and mix on medium-low speed until smooth and combined. Scrape down the sides of the bowl; add confectioners’ sugar, vanilla paste, salt, and cream. Mix until all ingredients are fully incorporated and smooth, 1 to 2 minutes.

Once the cakes have cooled, place 1 vanilla layer onto a cake stand. Spread half the chocolate ganache (about ¾ cup or 172 grams) on top. Add 1 red velvet layer on top. Spread a generous dollop (about 1 cup or 233 grams) of cream cheese frosting on top.

Add remaining red velvet layer onto frosting and then spread with remaining chocolate ganache. Place the remaining vanilla layer on top. Spread the remaining frosting on the top and sides of the cake. Refrigerate the cake for 30 minutes before serving. Cover and refrigerate for up to 3 days.