Crumb coat your cake and let it set in the fridge.
Once it's set remove from the fridge and add a layer of the swiss meringue buttercream just to the middle third of the cake.
Mix the glamour and sparkle sprinkles with some of the red and green bright and bold sprinkles. Alternatively, just use the glamour and sparkle sprinkles. Take the sprinkles and using your palm, pat onto the band of buttercream to form a thick layer of sprinkles.
Put in the fridge for 30 minutes to firm up. Remove from the fridge and then add a thick layer of the swiss meringue buttercream to the top and remaining top and bottom thirds of the cake up to the edge of where the sprinkles are.
Smooth with a palette knife or cake smoother, leaving the edge of the buttercream near the sprinkles rough and uneven.
Take the edible gold paint and paint onto the rough edge of the buttercream next to the sprinkles. Put the remainder of the swiss meringue buttercream in a piping bag fitted with the closed star nozzle and pipe 8x rosettes or ‘trees’ onto the top of the cake. Scatter with some more sprinkles.