Preheat oven to 350°. Line a high-sided 9-inch round cake pan with parchment paper cut to fit and grease with cooking spray.

Line the bottom of the prepared pan with apple wedges, arranging them in concentric circles, then shingle any remaining slices in the center.

In a medium saucepan, combine the granulated sugar with 3 tablespoons water. Cook over medium-high heat, shaking the pan as needed, until an amber caramel forms, 6 to 8 minutes. Immediately pour the caramel over the apples in an even layer.

In another medium saucepan, melt the butter over medium heat. Cook, stirring continuously, until browned and nutty in aroma, 6 to 8 minutes. Pour the melted butter into a heatproof large bowl and let cool slightly, then whisk in the honey, buttermilk, eggs, brown sugar, and vanilla until smooth.

In a medium bowl, whisk together the flour, salt, cinnamon, nutmeg, baking powder, and baking soda to combine. Add the dry ingredients to the wet ingredients and fold until just incorporated. Pour the batter over the caramel-coated apples. Bake for 1 hour to 1 hour 10 minutes, until the top is golden and a toothpick inserted into the center comes out clean.

Let cool in the pan for 15 minutes, then run a paring knife around the edge of the cake. Place a plate over the cake pan and invert them together, then lift off the pan and remove the parchment. Let the cake cool slightly, then serve warm. Top with whipped cream and drizzle with honey, if desired.