Preheat the oven to 400 degrees F, and spray a muffin tin with nonstick spray. You will only be using 6 of the muffin molds.
Place a slice of ham into each cup, pressing to fit along the shape of the muffin tin mold.
Whisk together the eggs, heavy cream, sugar, vanilla extract, salt, and ground cinnamon in a large bowl until thoroughly combined. Add the torn pieces of croissant to the bowl. Stir until evenly coats. Let the croissants soak up the wet mixture for about 15-20 minutes.
Evenly spoon the ham cups with the croissant mixture. Use a slotted spoon for this step so that you don't spoon any unnecessary excess egg mixture. Sprinkle the coarse sugar on top.
Bake the cups for about 15-20 minutes or until brown and crispy. Serve immediately with fresh berries, whipped cream, maple syrup, or whatever your heart desires!