Preheat oven to 350F. Spray a 10" tube pan with nonstick spray.
In a large bowl, beat the butter and sugars until sandy. Beat in the eggs and vanilla.
In a smaller bowl, whisk together the flour, cinnamon, ginger, baking powder, baking soda and salt. Add about a third to the butter mixture and beat on low just until blended. Add half the sour cream, another third of the dry ingredients, the rest of the sour cream, and the rest of the dry ingredients, stirring by hand or beating on low just until combined. Scrape the batter into the pan.
Slice the apples onto the surface, arranging them however you like - they will shrink as they cook, so feel free to place them tightly together. Drizzle with caramel sauce. If you're using the sugar and butter, bring it to a simmer in a small saucepan, then drizzle it overtop.
Bake for 45 minutes, until the cake is springy to the touch.