Slice challah bread into 4 thick slices, then cut a pocket in the top of each slice. Whip together the cream cheese, 1 teaspoon of cinnamon, and sugar. Spread the mixture into the pockets and place the sliced strawberries on top. Whisk eggs and half-and-half with additional teaspoon of cinnamon. Dip bread into egg mixture and cook on griddle coated with vegetable spray until golden brown. Warm the maple syrup and chopped walnuts. Remove French toast from griddle, place on a platter, and dust with powdered sugar. Serve with warmed syrup and walnuts.