You can create a chocolate dome cake with silicone molds and have it shaped as a half sphere.
Chocolate mousse is stable when making it with gelatin. Use a chocolate mousse recipe that has been stabilized with gelatin to create your chocolate dome cake.
Begin by making your chocolate mousse and letting it chill for a couple of hours.
You can make a cake bottom to go with your chocolate dome cake. Your cake bottom could be an cookie crumble mixed with butter to stabilize it. Another option is almond dacquoise. It’s a little bit harder than a cookie crumble and has more thickness to it.
Once you’ve baked the crust for your chocolate dome cake, let it cool to room temperature. Use a metal cookie cutter or a glass to gently cut the cookie into pieces that will fit perfectly for your silicone mold. Try to get it as exact as possible or a little smaller.
Assemble the chocolate dome by spooning the mousse into the silicone mold. You could use a half sphere silicone mold to give it a dome cake look.
Leave about 1/4″ thickness from the top of your mold to add the cookie to the mold at the very end.
Guide the mousse up the sides of the silicone mold leaving about 1/4″ thickness from the top. Make sure there’s a thick layer on the edges, and leave enough room for the center of your chocolate dome cake.
Spoon the center into the silicone mold until it’s about level with the mousse.
Add the cookie and press it into the center and mousse a little. It’s ok to have the mousse come around the edges.
Freeze the mousse cake for about 4 hours to let it set.
Remove the chocolate dome cake from the freezer and gently peel back the silicone mold.
You can add a mirror glaze to the top of your dome cake, or a simple syrup to make it shine. You can dust the top with powdered sugar, cocoa powder, coconut flakes, or add a small amount of whip cream to the top to finish it off.
Your chocolate dome cake is ready to be served.