Preheat the oven to 350 degrees F. Grease three 9-inch round cake pans and cut parchment paper circles to fit down in the bottom of each pan. Flatten the circles in the bottom of the pans to remove air bubbles.
Mix the cake flour, espresso powder, cinnamon, baking powder, and salt together in a bowl. In the bowl of an electric stand mixer, cream the butter and sugars together on high until light and fluffy, 3-5 minutes. Scrape the bowl and beat on low, adding in the milk, eggs, and vanilla extract. Slowly add in the flour mixture. Scrape the bowl again and beat until well combined.
Pour the cake batter evenly into the three prepared pans. Bake for 20-25 minutes, until a tooth pick inserted into the middle of the cake comes out clean. Cool in the pans for 10 minutes. Then gently flip onto cooling racks and peel off the parchment paper.
Once the cakes cool to room temperature, move on to the frosting. With an electric mixer, beat the mascarpone cheese and cream together until smooth. Add the salt. Slowly beat in powdered sugar until the frosting is firm enough to spread and set.
Gently flip one cake layer onto a cake plate. Add one-quarter of the frosting and spread to the edges. Flip the second cake onto the first layer. Spread one-quarter of the frosting over the second cake. Repeat with the last cake layer and the remaining one-half of the frosting. Allow the frosting to hang over the edges (like snow) with exposed edges, or smooth the frosting down over the sides for a rustic finish. Refrigerate to set the frosting. Then cover and keep refrigerated.
When ready to serve, let the cake sit out at room temperature for at least one hour. Decorate the top with plastic trees and sprinkle powdered sugar snow over the top.