• Preheat the oven to 350F Grease a 9 inch cake pan (that's at least 2 inches deep) and set aside.

For the topping:

• In a small saucepan, mix butter and brown sugar together over medium heat. Whisk occasionally, until butter has melted. Then cook while constantly whisking for 1 minute as mixture thickens. Remove the heat, and mix in the cinnamon. Pour into a the prepared pan and set aside to cool while you prepare the apples. 
• Peel, core and slice the apples into ¼ inch slices. Add the lemon juice to the apples and toss to coat. Arrange the apples into the cooled sauce in a decorative pattern. Set aside.

For the cake:

• In a medium mixing bowl, mix the flour, baking powder, cinnamon, salt, brown sugar, and sugar.
• In a large mixing bowl, mix together the apple juice, vanilla, and egg. Mix well to combine. Add the flour mixture and mix to combine.
• Gently spread the batter over the apples (being careful not to shift the apples out of place). Bake 30-40 minutes or until a cake tester comes out clean.
• Remove cake from the oven and cool on a cooling rack for 15 minutes. Invert the warm cake onto a cake stand or serving plate. Some of the juices from the topping will go down the sides of the cake – that’s just fine. Slice and serve the cake warm.