Prepare the Cake:

• Preheat oven to 350°F (175°C). Grease and flour two 9-inch (23cm) round cake pans.
• In a bowl, whisk together flour, baking powder, and salt. Set aside.
• In a large mixing bowl, cream the butter and sugar until light and fluffy. Add eggs one at a time, mixing well after each. Stir in vanilla extract.
• Mix in the dry ingredients alternately with milk and sour cream, starting and ending with dry ingredients. Fold in the toffee bits.
• Divide the batter evenly between the prepared pans and bake for 30-35 minutes or until a toothpick inserted in the center comes out clean.
• Let cakes cool in pans for 10 minutes, then transfer to a wire rack to cool completely.

Make the Caramel Sauce:

• In a saucepan over medium heat, combine sugar and water. Stir gently until sugar dissolves, then stop stirring and let the mixture cook until it turns a deep amber color.
• Carefully add the heavy cream (it will bubble up), then whisk in butter, salt, and vanilla. Set aside to cool.

Prepare the Caramel Buttercream:

• Beat butter until creamy, then gradually mix in powdered sugar.
• Add caramel sauce, heavy cream, vanilla extract, and salt. Beat until smooth and fluffy.

Assemble the Cake:

• Place one cake layer on a serving plate. Spread a layer of caramel buttercream over the top. Drizzle some caramel sauce.
• Place the second cake layer on top and frost the entire cake with the remaining buttercream.
• Drizzle caramel sauce over the top and sprinkle with toffee bits.

Serve & Enjoy:

• Slice and serve with extra caramel drizzle if desired!