In a medium saucepan over medium-high heat, whisk together the cream, milk, vanilla, and cocoa.
Bring to a boil, stirring.
Remove from heat, cover, and let sit for 30 minutes.
Chop bread into 1/2″ cubes. Transfer to a large bowl and set aside.
Bring mixture back to boil and stir in chopped chocolate.
Take off the heat and continue to stir until chocolate is melted.
Whisk together the egg yolks and sugar in a medium-sized bowl.
Slowly add the warm chocolate mixture, whisking constantly until combined.
Pour the mixture carefully over the bread cubes.
Stir until all cubes are covered.
Cover with plastic wrap and set aside for 15 minutes.
Mix in as much toffee as you'd like. I made sure that there were a few small pieces in each cupcake.
Stir to combine.
Scoop soaked bread cubes into cupcake liners until bread cubes are level with the top of the rim.
Carefully pour the remaining liquid into each cupcake, filling until nearly full.
Bake at 350 F for about 22 minutes or until set.
Notes
Top the bread pudding cupcakes with [brewed chocolate frosting|https://www.cupcakeproject.com/what-to-drink-with-your-cupcakes/. (See picture in this post)