In a shallow large bowl, combine powdered sugar cornstarch and cinnamon and whisk to combine. Add three eggs, milk, vanilla extract and whisk until well combined.
Dip each slice of bread into the egg mixture one at a time then add to a large skillet. Depending on the size of your skillet you may need to cook the french toast in several batches.
Cook the french toast over low-medium heat for 3-5 minutes until golden and crispy. Flip and cook on the other side for an additional 3-5 minutes. Once the french toast is complete remove from the skillet and place on a large plate. Cover the plate to keep the french toast warm and set aside.
For the Eggs
While the french toast is cooking, add remaining eggs, milk and sea salt to a prep bowl and whisk to combine. Add the eggs to a separate pan and scramble.
Once the eggs are nearly cooked top with mascarpone cheese dollops and stir until cheese is melted. I like to turn the heat up real high the last minute to crisp the bottom of my eggs, but this is not required.
Assembling the French Sandwiches
If you are frying bacon or making it in an air fryer, do so while the eggs and french toast are cooking. Personally, I like to make mine ahead of time or use leftover bacon to save time, but wither method works.
Once all the ingredients are cooked it is time to assemble the stuffed french toast. Spread one slice of french toast with cream cheese, the other with blackberry jam then top with cooked bacon and scrambled eggs. Repeat until all the sandwiches are filled with cream cheese, jam, eggs, and bacon
Press the two sides together to create a sandwich then cut in half and top with maple syrup, powdered sugar and fresh blackberries and serve warm. Enjoy!