Preheat oven to 350º F. Grease a 10-inch cake pan.
To make caramel, in a small saucepan melt 4Tbsp. butter and add brown sugar. Simmer about four minutes, stirring occasionally, Stir in salt and remove from heat. Pour caramel mixture into the bottom of cake pan and arrange apple slices evenly on caramel. Chop up any remaining apple and use to fill in any gaps.
To make gingerbread, In a large bowl, cream together 1/2 cup butter and sugar with a mixer until light and fluffy. In another medium bowl, combine egg, buttermilk and honey. Alternate adding Hodgson Mill Gingerbread Mix and the buttermilk mixture to the creamed butter and sugar, mixing after each addition.
Pour the batter into prepared pan over the apples. Bake at 350º F for 50-60 minutes or until sides of cake pull away slightly from the edges of the pan and a toothpick inserted into cake comes out clean Let the cake cool for five minutes on a rack and then turn out onto a platter, with caramel and apples up. Add any extra apples and/or caramel from the pan the cake.
Serve warm or cool with a scoop of vanilla ice cream.