1. Preheat oven to 350℉. Spray three 8” round cake pans with cooking spray and line the bottoms with parchment paper. 2. In a medium bowl whisk to combine flour, baking powder, baking soda, and salt. 3. In a large bowl or a stand mixer fitted with the paddle beat butter on medium speed until smooth. Gradually add sugar, increase speed to high, and beat, scraping down sides of bowl occasionally, until light and fluffy, about 3 minutes. 4. Beat in vanilla, then beat in eggs 1 at a time, scraping down sides of bowl after each addition, until incorporated. 5. Scrape down sides of bowl again. On low speed, add flour mixture in 3 parts alternating with buttermilk in 2 parts. 6. Divide batter between prepared pans and spread evenly. 7. Bake until a toothpick inserted in the center comes out clean, 25-30 minutes. 8. Let cakes cool in pans on a rack for 10 minutes. Invert cakes, peel off parchment, and turn right side up to cool completely. 9. In a large saucepan combine sugar and 2 cups water. Bring to a boil and boil 5 minutes. Add cranberries, zest, and cinnamon stick, and simmer gently until berries have burst and sauce is thickened, about 15 minutes. Transfer to a large, wide dish and let cool completely. Remove cinnamon stick and drain cranberries of any excess liquid. 10. When cakes and cranberry sauce are completely cooled, prepare whipped mascarpone: In a large bowl or a stand mixer beat cream, mascarpone, sugar, and vanilla paste on medium speed until stiffly whipped. Refrigerate until needed. 11. To make the decorations, in a small saucepan combine ½ cup sugar and ¼ cup water. Bring just to a simmer, stirring to dissolve sugar, then transfer to a bowl and let cool completely. 12. Place remaining ½ cup sugar on a plate. Roll cranberries in sugar syrup and use a fork to lift them out, allowing excess syrup to drip off. Roll cranberries in sugar and transfer to a parchment-lined baking sheet. Dip rosemary in syrup and allow excess to drip off. Hold rosemary over plate with sugar and sprinkle sugar over the rosemary to coat lightly. Transfer to baking sheet to dry. 13. To assemble cake, place 1 cake on a serving platter or cake stand upside down so the flat side is facing up. Spread a layer of mascarpone over top of cake, then top with half the cranberry sauce, spreading it to 1” from edge of cake layer. 14. Place another cake on top, spread a very thin layer of mascarpone on top, and top with remaining cranberry sauce, spreading it to 1” from edge of cake layer. Place last cake on top. 15. Frost cake with remaining mascarpone, smoothing it with a large offset spatula. Cake may be refrigerated up to 4 hours before serving. 16. Right before serving, decorate with frosted cranberries and rosemary.