Preheat oven to 350°F. Prepare two 8 in. round pans with vegetable pan spray.

In a large bowl, stir together flour, brown sugar, baking powder, cinnamon, ginger, salt and nutmeg.

In another bowl, whisk pumpkin with whole eggs until well combined. Add to flour mixture and whisk until well combined.

In large bowl, whip egg whites on high speed until foamy, about 1 minute. Add cream of tartar and beat to soft peaks. With mixer running, gradually add granulated sugar. Continue beating until glossy and stiff.

Fold 1/3 of the egg whites into pumpkin mixture until no white streaks remain. Fold in remaining egg whites completely. Pour into prepared pans.

Bake 28-32 minutes, or until toothpick inserted into the center of cakes comes out clean. Invert pans on cooling grid and cool completely. When cooled, run a knife along sides of cake to release from pan.

In a large mixing bowl, whip egg yolks and whole eggs on high speed with an electric mixer until very thick and pale, about 6 minutes.

In a heavy saucepan, combine sugar, water, corn syrup and salt; stir gently to combine. Cook over medium heat, occasionally brushing down sides of pan with pastry brush and water, until deep amber in color (about 330°F). Immediately remove pan from heat and carefully measure 3/4 cup caramel into a glass-measuring cup. Add 1/4 cup warmed heavy cream; mixture will boil up. Set aside and cool to room temperature.

With the mixer on medium speed, slowly drip remaining caramel down the side of the mixing bowl and into whipped eggs, being careful to not let syrup fall directly into the eggs or onto the whip. Continue whipping on medium speed until outside of mixing bowl is room temperature, about 10 minutes. Reduce mixer speed to medium-low; add butter, one chunk at a time, beating until each addition is incorporated before adding the next. Add vanilla.

In a large skillet, toast pecan halves lightly over medium-low heat for 3 minutes. Add sugar, salt and cinnamon and stir to combine. Increase heat to medium. Cook, stirring occasionally, until sugar is deep amber and nuts are coated. Dump nuts onto parchment paper and separate with spatula. Cool completely.

To assemble cake, torte pumpkin chiffon layers with Ultimate Cake Leveler or serrated knife. Position first cake layer a top a rimed plate. Spread a thin layer of caramel silk buttercream on top. Repeat with remaining cake layers and icing. Ice top and sides of cake. Refrigerate until icing is firm.

When icing is cold and caramel sauce is at room temperature, pour about half of caramel sauce over the top of the cake and smooth to the edges. Allow caramel to drip down sides of cake and let set for 5 minutes. Using tip 1M, pipe 12 balls of caramel icing around the top of the cake. Top each with a candied pecan half. Serve immediately, or refrigerate until 30 minutes before ready to serve. Serve with additional candied pecans and caramel sauce.