In a medium saucepan, combine granulated sugar, 6 tablespoons of salted butter, and 1/4 cup heavy cream. Cook over medium heat, stirring gently until the mixture begins to bubble and turns a lovely amber color, about 8-10 minutes. Remove from heat and sprinkle in a pinch of flaky sea salt. Let it cool while you prepare the other components for the ultimate pumpkin cake.

In another saucepan, mix 1 cup of brown sugar, 1/4 cup water, and 1 teaspoon cinnamon. Bring to a simmer over medium heat, then add 1 cup of pecan halves and 1/2 cup of pepitas, stirring to coat. Cook for about 5 minutes until the mixture thickens slightly. Pour the nuts onto a parchment-lined baking sheet, spreading them in an even layer. Allow them to cool completely before chopping.

Preheat your oven to 350°F (175°C). In a large mixing bowl, whisk together 4 eggs, 1 cup of brown sugar, 1/2 cup of vegetable oil, 1/4 cup of maple syrup, 2 teaspoons of vanilla extract, and 1 can of pumpkin until smooth. Gradually mix in 2 cups of all-purpose flour, along with 1 teaspoon baking powder, 1/2 teaspoon baking soda, and the chosen spices until just combined, ensuring not to overmix.

Divide the pumpkin cake batter evenly between three greased and floured 9-inch round cake pans. Place the pans in the preheated oven and bake for 20-24 minutes, or until a toothpick inserted into the center comes out clean. Once baked, remove the pans from the oven and allow the cakes to cool in the pans for 10 minutes before transferring them to wire racks to cool completely.

In a large bowl, beat together 1/2 cup of softened salted butter and 8 oz of cream cheese until smooth and fluffy. Gradually add in 3-4 cups of powdered sugar, beating until well combined. Mix in 1/4 cup of heavy cream, 1 tablespoon of maple syrup, 1 teaspoon of cinnamon, and a pinch of salt, adjusting the sugar to achieve your desired sweetness for the ultimate pumpkin cake frosting.

Once the cake layers have cooled, place one layer on a serving plate and spread a generous layer of frosting on top. Drizzle with reserved salted caramel sauce and sprinkle with half of the candied pecans. Add the second layer and repeat the process. Finally, place the third layer on top, crumb coat the entire cake, and refrigerate for about 30 minutes. Finish by applying a thick layer of frosting, drizzling with more caramel, and topping with the remaining pecans and pepitas.