Cut each baguette into 1-inch slices, cutting to, but not through, bottom of loaf. If using a longer baguette, cut to fit in a 9x13 pan.
Prepare the filling by beating the mascarpone cheese, 1 tsp. vanilla and almond extract until smooth. Beat in the powdered sugar and lemon zest; fold in the berries.
Spoon the filling between the baguette slices; arrange the baguettes side by side in a 9x13 pan.
In a large bowl, whisk together the eggs, milk, 1/2 cup sugar, 1/2 tsp. cinnamon, and 1 tsp. vanilla extract. Pour over the bread; cover and chill overnight (up to 2 days).
Preheat oven to 350 degrees.
Remove French toast from refrigerator while oven heats. With remaining 1/4 cup sugar and 1 tsp. cinnamon, mix together; sprinkle over the French toast.
Bake, uncovered, 30-40 minutes, or until puffed and golden and a knife inserted in the center comes out clean. Cover with foil and bake another 5-10 minutes if needed (and eggs are set).
Remove; cool. Serve with your favorite maple syrup!