Preheat oven to 350F. Line 2, 8-inch round cake pans with parchment paper; set aside.
In a large bowl, cream together the butter, sugar and extracts until light and fluffy. Mix in the eggs until well combined, then mix in the milk and maple syrup. In a separate bowl, combine the dry ingredients: flour, baking powder and salt. Use a sifter to add the flour into the cake batter; mix in the flour just until combined. Fold in the chopped pecans at the end.
Divide the cake batter evenly between the two prepared pans. Bake in preheated oven 35-40 or until completely set. To check for doneness, insert a toothpick into the center; it needs to come out clean. Remove cake layers from pans and set onto wire rack to cool completely.
For Caramelized Sugar:
Meanwhile, work on sugar garnish. Wrap 2 large water glasses with parchment paper and set onto baking sheet. In a small saucepan, combine 1/2 cup white granulated sugar with 3 tablespoons water. Cook the mixture, not stirring, over medium-low heat until the sugar caramelizes and turns a dark amber color. Remove the sugar from heat and let cool for about a minute until the sugar thickens slightly. Using a spoon, drizzle the sugar syrup over the wrapped glasses, building up the layers. If sugar hardens too quickly, return to heat for 30 seconds. Let the sugar harden, then carefully slide the parchment paper off the water glass and peel away from sugar. Break sugar into desired pieces.
For Caramel Frosting:
For the frosting: place the butter, dulce de leche and salt into a mixer bowl and whisk until light and fluffy, scrapping down sides of bowl often. Add the cream, then start adding powdered sugar until frosting reaches desired thickness. If frosting starts to melt, place into refrigerator for 20 minutes.
Assembling the Cake:
Cake can be assembled as a 2-layer or 4-layer. For four layers, simply split the cake layers in half using a long, serrated knife. Spread a generous amount of frosting between each layer and over the top and sides of cake. Use a flat spatula to even off the top and sides of the cake, then set into refrigerator for 20 minutes to allow the frosting to set.
Garnish with caramelized sugar, then set cake into refrigerator for a few hours to set completely.