Make the Salted Caramel Sauce: Follow the directions and recipe in this post to make the Caramel Sauce! Let cool, then store in a jar in the fridge until ready to use (or up to 1 month).

Make the Candied Pecans & Pepitas: Line a baking sheet with parchment paper. Add the brown sugar, water, vanilla extract, and cinnamon to a medium saucepan over medium heat. Let cook, stirring, for 1-2 minutes, until bubbling. Stir in the pecans and pepitas to coat, then continue stirring and cooking for 2-3 minutes. Place on prepared pan to cool and set up.

Make the Cake Batter: Preheat oven to 350° F. Grease & flour three 9-inch round cake pans.In a large mixing bowl, whisk together the eggs, brown sugar, oil, maple syrup, vanilla, and pumpkin. Add the dry ingredients and whisk together just until the batter smooths out, making sure no dry bits are hiding in the bottom of the bowl.

Bake: Divide the batter between your prepared pans, and bake for 20-24 minutes. A toothpick inserted into the center of the cakes will pull out moist crumbs, not wet batter. Let cakes cool in the pan for 10 minutes before inverting onto a wire rack to cool completely.Note: I prefer to bake two pans on the same rack at one time, then do the third one separately after that, for the most even bake.

Make the Frosting: In a large bowl, cream the butter for 1 minute or so. Add the powdered sugar, 2 cups at a time, mixing between each addition, using the maple syrup to help it combine. Mix in the cinnamon, vanilla extract, and a pinch of salt to taste. Add the cream cheese last, to prevent weepy frosting. Taste and adjust if desired.Tip: If your frosting becomes too soft to work with, pop it in the fridge/freezer to chill and stiffen up.

Assemble the Cake: Place the first cake layer on a cake stand protected with wax paper strips, or a turntable (or even on the cake stand, on top of the turntable). (A turntable is the easiest!) Use a dab of frosting to secure the layer in place. Fill a piping bag fitted with a round tip with ½ cup of frosting. Frost the first layer with 1 cup of frosting, spreading it evenly with an offset spatula. Pipe a border of frosting around the cake layer and fill with ½ cup of caramel sauce. Add ½ cup of the nuts. Place the second cake layer on top and spread the excess frosting peeking out between the layers to begin your crumb coat around the first two layers. Chill for 5-10 minutes to set things so the layers don't slide around. Repeat with the second layer. Add the final layer upside down (for a flat top!) and give the cake a thin layer of frosting on top and on the sides.Use a cake scraper to smooth out and remove excess frosting. This is your crumb coat, so don't fret if it isn't perfect. Pop the cake in the fridge for 30 minutes to set the frosting. Then, apply the remaining frosting, using the cake scraper to smooth the top and sides of the cake. Create a drip around the edge of the cake with the remaining caramel sauce – simply pour it slowly along the edge while turning the cake, and let it drip down. Pipe extra frosting in swirls on top of the cake and decorate with the remaining nuts and a pinch of flaky sea salt. Chill the entire cake in the fridge for 30 minutes, or longer if your frosting got soft while working with it (with plastic wrap or a cake lid).Note: All tools mentioned here are named and linked in the "special tools" section of the post, just above the recipe card.

Serve + Store: Serve the cake once it's had at least 30 minutes in the fridge to set up. Slice and enjoy! Store leftovers in an airtight container in the fridge for 3-4 days. Press plastic wrap over the cut part of the cake to help preserve it, even if it's enclosed in a cake container. See tips for freezing in FAQs above.