Place butter and chocolate chunks in a small sauce pan and heat on low until the butter is almost melted. Set aside and whisk until combined.
In a mixing bowl, whisk together the almond flour, chestnut flour and powdered sugar. Make a well, add the egg whites and the cooled butter/chocolate mixture. Mix gently until smooth.
Spoon your Batter into your Flexipan®. Arrange your sliced peach on top (1 slice per well).
BAKE!
Bake for 23 minutes at 350F/180C. (Every oven heats differently, monitor your cakes from 20min). It is ready when the toothpick inserted into the center comes out clean.
Once your GF Chocolate and Peach French Cakes are out of the oven, let them cool down for about 10min. Then, Unmold, Serve and Enjoy! Bon Appétit!