A mirror glaze is a classic french technique that can seem quite intimidating!! I've simplified my mirror glaze recipe to make it super easy to make, and it only uses 5 ingredients!! It also can be made using just a microwave!
Begin by mixing the gelatin in a bowl with 1/4 cup of water. Set aside to let it bloom while you begin the glaze. Pour the sugar, 3/4 cup of water, and sweetened condensed milk in a heat proof bowl. Heat for 1 minute on high power in the microwave.
Remove the mixture, and stir to incorporate the ingredients. Pour in the bloomed gelatin, and stir until it's fully dissolved.
Melt the white chocolate chips in microwave by heating and stirring in 30 second intervals. Once the white chocolate is fully melted, pour the chocolate into the warm gelatin mixture. Carefully whisk mixture until fully combined.
Continue to stir occasionally to stop a skin from forming, until the glaze has reached 85 degrees, or is about room temperature.
Divide the glaze evenly between three bowls. Color them different shades of green using gel food coloring.
Once the glazes have cooled slightly, pour them back into one large bowl, alternating colors and drizzling the colors together as you combine them.
Place fully chilled buttercream cake (chilled in the freezer at least 1 hour) on top of a circular object smaller than the cake board, and set this on top of large baking sheet (to catch the run-off glaze).
Begin pouring the glaze onto the center of the cake, then slowly work out to the edges of the cake in a circular motion. Let the glaze continue to drip for about 10 minutes, then scrape away excess glaze from the bottom of the cake board using a small offset spatula.
Place the cake in the fridge, to allow the glaze to set, and to slowly thaw the cake.