Chop the chocolate into small pieces while the dough is chilling in the fridge. Preheat the oven to 375F at this time.
1½ cup Semi Sweet Chocolate
Cut out 2 pieces of parchment paper, each large enough to cover a 9"x13" baking tray. Place one piece on the counter, sprinkle with flour, and place the chilled dough on top.
Sprinkle flour on top of the chilled disk of dough and place the other piece of parchment on top, aligning with the bottom parchment.
Use a rolling pin to roll out the dough to a 13-14 inch circle. Transfer the dough with the bottom parchment, onto a 9"x13" baking tray.
Sprinkle the chopped chocolate on the rolled out dough, leaving a 2 inch border of dough all around.
Slice the peeled bananas at a slight diagonal, into ½ inch slices. Place the banana slices over the chopped chocolate to cover it completely.
3 large Bananas
Lift a 3 inch section of the border dough and fold it over the bananas. Take small section beside it and fold it over. Keep folding small section all around the galette, with a small overlap.
Sprinkle the brown sugar evenly over the banana sliced. Whisk the egg yolk and 1 teaspoon of water to create an egg wash and brush it over the folded edge of dough.
2 tablespoon Brown Sugar, 1 piece Egg Yolk, 1 teaspoon Water
Transfer the Banana Chocolate Galette to your preheated 375F oven and bake for 35-40 minutes, or until the dough is a nice golden color. Let the galette cool dough for 10 minutes once ready, so that the chocolate can start to cool down.