In a saucepan, whisk together the cream, brown sugar and egg yolks until smooth. Cook over medium low heat, whisking constantly, until thick and bubbly, about 5 minutes.
Remove from the heat and stir in the butter, vanilla, bourbon, pecans, coconut and salt. Cover and let cool at room temperature for several hours.
Chocolate Buttercream
In the bowl of your stand mixer fitted with the paddle attachment, beat the butter until smooth.
With the mixer on low, add the powdered sugar, cocoa powder and meringue powder until combined. Add the salt, vanilla and milk, and whip on medium high until light and fluffy, about 4-5 minutes.
Assembly
To assemble, use a cupcake corer to remove the centers of each cupcake. Spoon some of the caramel filling into the centers.
Fit a large piping bag with tip 1M, and fill with chocolate buttercreams. Pipe a swirl of buttercream around the edge of the cupcakes.
Spoon more of the caramel filling into the center.
If you like, sprinkle the top of the cupcakes with toffee bits.
Video
Notes
Store leftover cupcakes in an airtight container at room temperature for up to 3 days.If your caramel filling is too thin or runny, you likely didn't cook it for long enough. Return it to the stove and cook for several more minutes over medium low heat until thickened.
Keyword Caramel, Chocolate Cupcakes, Cupcakes, German chocolate, High Altitude