Preheat oven to 350°. Toss chopped apples with lemon juice in a medium bowl. Add brown sugar, stirring well to coat.
Whisk together pancake-and-waffle mix, granulated sugar, and cinnamon in a medium bowl; stir in milk, butter, and vanilla. Fold apple mixture and any accumulated juices into batter. Spread into a lightly greased 8-inch square pan.
Microwave apple juice in a 2-cup glass measuring cup at HIGH 2 to 3 minutes or until boiling. Using a spoon, gently drizzle hot apple juice over batter in pan. (Some batter may float once juice is added.)
Bake at 350° for 30 to 35 minutes or until a cake layer forms on top and layer springs back when touched. Let cool on a wire rack 25 minutes. Serve warm with ice cream, if desired.
Note: For testing purposes only, we used Aunt Jemina's Original Complete Pancake And Waffle Mix.
My family absolutely loves this and it is soooo easy and quick. We look forward to Fall with the best apples available. It is easy to take places also.