I make that, too. I do it a bit differently, as I wanted to cut down on the almond flour: 1 1/2 tablespoons butter, 1 egg, 2 tablespoons almond flour, 1 tablespoon coconut flour, 1/2 teaspoon baking powder, 1 tablespoon water. I mix it up in a small bowl as I couldn't get the egg fully mixed in using a mug. I use a mug because I don't have anything else with a better size. I cut it into 4 slices. Yesterday I made salmon melts - lovely!

I'll have to check our dollar store & see if they have a silicon pan like you have. Or if I double the baking powder, maybe it would work in my small soufflé dishes.