In a large mixing bowl, whisk together the eggs, molasses, milk yogurt and melted butter. Slowly add both dry mixes and spices, then stir until all incorporated.
Heat a griddle or skillet on medium high and spray with non-stick cooking spray. Pour the batter onto the griddle or skillet, using approximately 1/4 cup for each pancake. Cook 1-2 minutes on each side, then arrange cooked pancakes on a wire rack to cool.
While the pancakes are cooling, whisk all of the custard ingredients together in a large bowl, set aside.
Spray a 9x13 pan with non-stick cooking spray. Slice pancakes in half and arrange in prepared baking dish in rows with the flat side down. Pour custard mixture over the pancakes, then cover with plastic wrap and refrigerate overnight or at least two hours.
In a small bowl, using your hands, mash together the flour, brown sugar, cinnamon, salt and butter until a crumble forms.
Preheat the oven to 350 degrees and allow pan to return to room temperature. Sprinkle the prepared crumble over the top of the arranged pancakes. Bake for 50-60 minutes. Cool 20 minutes before serving. Serve with powdered sugar and maple syrup.