Sky-High Salted Caramel Chocolate Layer Cake

Heat oven to 350°F (180°C). Spray four 8- or 9-inch (20 or 23 cm) round cake pans with cooking spray. If desired, line bottom of each pan with cooking parchment paper for easier cake removal.

In large bowl, make cake batter as directed on boxes; divide among pans. Bake 32 to 38 minutes or until toothpick inserted in the centre comes out clean. Cool in pans 10 minutes. Run knife around edges of cakes to loosen. Remove from pan to cooling rack; cool completely, about 1 hour.

Meanwhile, in large bowl, beat Salted Caramel Cheesecake Filling ingredients with electric mixer on medium speed just until smooth and well combined

Use serrated knife to level tops of cakes, if necessary. Place one layer, cut side down, on platter or serving tray. Top with one-third of the filling. Repeat with remaining cake layers and filling, finishing with a cake layer.

To make Salted Caramel Buttercream: In large bowl, beat shortening and butter with electric mixer on low speed until smooth. Gradually add icing sugar, 1 cup (250 mL) at a time, beating until combined; beat in vanilla. In large microwavable bowl, microwave caramels and 1 tablespoon (15 mL) of the milk uncovered on High about 1 minute or until caramels are melted; stir until smooth. Stir caramel mixture and coarse salt into buttercream mixture until combined, adding remaining milk, 1 tablespoon (15 mL) at a time, until smooth and spreadable. Frost top and side of cake with a thin layer of buttercream to make a crumb coat. Repeat, frosting the top and side of cake with a second layer of the buttercream.

In small bowl, mix chopped pecans and crushed pretzels. Press mixture around bottom and 2 inches (5 cm) up side of base of cake. If desired, reserve some of mixture for top of cake. Drizzle cake with caramel topping, and top with any reserved mixture. Sprinkle with additional coarse salt. Refrigerate until ready to serve. Serve with ice cream, if desired.