Here's a twist on the classic American pineapple upside-down cake, and it works well with most stone fruits. Nectarine skin is very smooth and thin, so peeling is optional; but if you use peaches, peeling is recommended. This cake is best eaten the day it is baked, but can be refrigerated overnight, covered tightly. Bring to room temperature before serving.
Position a rack in the lower third of the oven and preheat to 350 degrees F. Butter a 9x12-inch cake pan and set aside.
Place 4 tablespoons (1/2 stick) of the butter in a small saucepan, and melt over medium heat. Stir in the brown sugar and honey, and bring the mixture just to a boil. Simmer for 2 minutes or until it's bubbly, then pour the caramel into the prepared pan, spreading it evenly across the bottom.
Arrange the nectarine wedges atop the caramel in the pan in concentric circles, overlapping the slices slightly to form a spiral pattern.
Place the remaining 6 tablespoons of butter in the bowl of a mixer and add the sugar. With the paddle attachment, beat at high speed until the mixture is very light and fluffy, scraping down the sides of the bowl once or twice. Add the eggs, one at a time, beating well between each addition. Then beat in the vanilla.
Combine the flour, baking powder, baking soda, ginger, and salt in a bowl and whisk to blend. Add the dry ingredients and the milk to the bowl and mix for 10 to 20 seconds. Once the dry ingredients have been added, don't mix longer than 30 seconds or the cake will be tough.
Immediately transfer the batter to the prepared pan, spreading it out evenly. Bake until a skewer or toothpick inserted into the center of the cake comes out clean, 45 to 55 minutes.
Cool the cake on a wire rack for 5 minutes, then turn out onto a serving dish. The cake must be removed from the pan before it has cooled or the caramel may harden and stick to the pan. If any pieces of fruit remain in the pan, carefully arrange them back into place.