Preheat oven to 350º. Spray 3 (9-inch) round cake pans with baking spray with flour. Line bottom of pans with parchment paper, and spray pans again.
In the bowl of a stand mixer fitted with the paddle attachment, beat butter and sugar at medium speed until fluffy, 3 to 4 minutes, stopping to scrape down sides of bowl. Add eggs, one at a time, beating well after each addition. Add sour cream, food coloring, and vanilla extract, beating to combine.
In a medium bowl, whisk together flour, cocoa, baking soda, and salt. Gradually add flour mixture to butter mixture alternately with buttermilk, beginning and ending with flour mixture, beating just until combined after each addition. Divide batter among prepared pans (smoothing tops if necessary).
Bake until a wooden pick inserted in center comes out clean, about 25 minutes. Let cool in pans for 10 minutes. Remove from pans, and let cool completely on wire racks.
Spread Cream Cheese Frosting between layers and on top and sides of cake. Using a bench scraper, smooth sides to expose some of the cake layers. Refrigerate for 1 hour. Top with Sugared Cranberries and Rosemary before serving.
Recipe by Victoria at https://victoriamag.com/two-red-velvet-cake-recipe/