Sweet Potato Cake with Cream Cheese Frosting and Salted Caramel Sauce

For the cake, preheat the oven to 350°F. Spray two 8-inch round baking pans with baking spray and set aside. 

Sift the flour, cinnamon, baking powder, baking soda, ginger, nutmeg and salt into a medium bowl and set the dry ingredients aside. 

In the bowl of a stand mixer fitted with the paddle attachment (you can also use a hand mixer), mix together the sugars and melted butter in a large bowl until incorporated, scraping down the sides of the bowl as needed. Add the eggs and mix until incorporated, scraping down the sides of the bowl as needed. 

Mix the dry ingredients into the wet batter just until the batter comes together and most of the flour is incorporated (don't overmix the batter), scraping down the sides of the bowl as needed. Mix in the sweet potatoes until fully incorporated. (This should only take 30 to 60 seconds; remember, you don't want to overmix the batter.) 

Divide the batter between the prepared pans and bake until the center springs back when lightly tapped, 25 to 30 minutes. Let cool completely in the pans. 

Meanwhile, make the frosting and caramel sauce.  

For the frosting, in the bowl of a stand mixer fitted with the paddle attachment (you can also use a hand mixer), cream the butter until nice and silky. Add the cream cheese and mix until incorporated. Add the powdered sugar a cup at a time until mixed in. Scrape down the bowl, then add the vanilla extract and mix until nice and fluffy, about 2 minutes.  

For the caramel sauce, in a medium saucepan set over medium-high heat, combine the sugar and cold water and stir to combine. Cook, without stirring, until the sugar has turned a deep amber hue, about 10 to 12 minutes. Wash the sides of the pan down with a pastry brush dipped in cold water, as needed to prevent sugar crystallization.   

While the sugar cooks, warm the cream in a small saucepan or in the microwave. When the caramel is ready, slowly whisk in the warm cream, butter and salt and continue simmering the mixture until smooth, about 2 to 3 minutes. Off the heat, whisk in the rum (if using). 

When the cakes are cool, remove them from the pans. Level the tops, then cut each one in half horizontally, ending up with 4 total layers. Place a small dollop of frosting on a platter and top with a layer of cake. Frost the top and sprinkle with some pecans (if using). Top with another layer of cake and repeat the process. Repeat until all the layers are frosted, then frost the sides of the cake and the top, if you like. 

Drizzle the warm caramel sauce (if needed, warm gently) around the top of the cake so it runs down the sides. Sprinkle more pecans on the top (if using). Cut into slices and serve with more caramel sauce.