Combine the cake mix, eggs and water together in the bowl of a stand mixer. Using the whisk attachment, whip together on low speed until combined. Scrape down the bowl, add the milk and mix on medium high speed for 4 minutes. Add in the melted butter and raspberry paste, mixing until smooth. Divide batter in to eight greased and floured 5 in/13cm cake pans. Bake the cakes at 325ºF/ 162ºC for 18-25 minutes or until done. Allow to cool completely.
Combine the butter and buttercream base in the bowl of a stand mixer. Using a whisk attachment, whip together on medium high speed for 2-3 minutes or until smooth. Slowly add in the water, a little at a time until fully incorporated. Whip on high speed for 3-5 minutes.
Warm the red cocoa butter color to 90ºF-95ºF/32ºC-35ºC. Spread a thin layer of the cocoa butter on the transfer sheet, swirling to achieve desired effect. Spread a thin layer of tempered white chocolate on top. Allow the chocolate to set until it is tacky and has crystallized slightly. Cut into desired shapes. Flip the transfer over, leave flat, and allow the chocolate to crystallize completely before removing from transfer sheet.
Cut the cakes in half. Spread a layer of Buttercream on top of one half, placing the other half of cake on top. Spread more Buttercream on top and repeat with all of the cakes. Cut the cake strips to fit around the cakes and attach with a piece of tape. Garnish with Red Chocolate Décor Plaquette and desired chocolate décor.
