Caramel Cupcakes with Salted Caramel Buttercream

I have made cupcakes with salted caramel buttercream before, but I usually make a chocolate cupcake with the salted caramel buttercream.  This is another recipe from the Butch Bakery Cookbook and I really wanted to try it because it's a caramel filled cupcake with the salty caramel buttercream.  These cakes are good but messy and the frosting was too soft to be able to pipe onto the cupcakes.

Cupcakes:
1 3/4 cups all purpose flour
1 1/2 tsp baking powder
3/4 tsp salt
1 1/2 sticks unsalted butter, softened
1 1/2 cups sugar
3 large eggs
1 tsp vanilla extract
3/4 cup whole milk

Caramel Sauce:
1 1/2 sticks unsalted butter
1 1/2 cups firmly packed dark brown sugar
3/4 cup firmly packed light brown sugar
3/4 cup whole milk
1/4 tsp salt

Salted Caramel Buttercream:
3/4 cup caramel sauce
2 cups icing sugar
2 tbsp unsalted butter, softened
2 tbsp egg beaters
1/4 tsp salt

To make the cupcakes preheat oven to 350.

In a medium bowl sift together the flour, baking powder and salt, set aside.

In the bowl of an electric mixer beat the butter and sugar for 2-3 minutes.  Add the eggs and vanilla, beat until combined. Add the flour mixture and milk, mixing until just combined.  Fill lined cupcake pans 3/4 full and bake for 20-22 minutes.

To make the caramel sauce in a large saucepan over low heat, melt the butter.  Add the dark and light brown sugars, milk and salt and bring to a boil. Continue to boil for 2 minutes, remove from heat and let cool.

To make the buttercream, in the bowl of an electric mixer beat the caramel sauce, icing sugar, butter, egg beaters and salt until thick and creamy, about 3 minutes.

While the cupcakes are still warm poke each cupcake with a skewer about 6 times and drizzle a tablespoon of the caramel sauce over each one.  Let them cool completely and spread the tops of each cupcake with 2 tablespoons of the buttercream and sprinkle each one with coarse salt.