Preheat your oven to 325°F (165°C). Place 1 1/2 tablespoons of butter in a 9-inch round cake pan (at least 2 inches high). Put the pan in the preheating oven for a few minutes until the butter melts.
Carefully remove the hot pan from the oven. Swirl the melted butter to coat the bottom. Sprinkle 2/3 cup of brown sugar evenly over the butter. Arrange the apple slices on top of the sugar in a single, slightly overlapping layer.
In a medium bowl, whisk together the flour, baking soda, baking powder, cinnamon, ginger, nutmeg, cloves, and salt.
In a separate large bowl, beat the eggs and 1/2 cup of brown sugar until combined. Whisk in the molasses and the 3/4 cup of melted butter.
Add the dry ingredients to the wet ingredients and stir just until no dry streaks remain. Be careful not to overmix. Slowly pour in the boiling water and whisk until the batter is smooth.
Gently pour the gingerbread batter over the apples in the pan, spreading it evenly to the edges.
Bake for 60 to 75 minutes. The cake is done when a wooden skewer or toothpick inserted into the center comes out clean or with moist crumbs attached. The internal temperature should be between 200-210°F (93-99°C).
Let the cake cool in the pan on a wire rack for 10-15 minutes. Run a knife around the edge of the pan. Place a large serving plate over the pan and carefully invert the cake onto the plate.