Preheat toaster oven to 400°F.
Place bacon and apple slices on a foil-lined baking sheet and sprinkle both with brown sugar and bake for 15 minutes.
Then add pecans, making sure they get into some of that rich bacon fat in the pan, and bake for another 3 minutes.
Remove from oven and roughly chop the bacon into smaller pieces.
Assemble the stuffed french toast. First, spread a layer of mascarpone (or cream cheese) on both slices of bread. Then, layer remaining ingredients (apple slices, bacon, and pecans), and add the second slice of bread on top, like a sandwich.
Preheat a pan on the stove to medium heat.
In a shallow bowl, whisk together egg and milk.
Dip one side of the “sandwich” into the egg mixture, then flip and dip the other side as well.
Place in the preheated pan and cook for about two minutes per side. Serve with maple syrup. Bon appétit!