Place biscuit pieces in a greased 8-inch baking dish.
In a medium bowl, whisk together eggs, milk, heavy cream, dark brown sugar, vanilla and cinnamon.
Pour mixture over biscuits. Sprinkle toffee bits and chocolate chips on top.
Use a wooden spoon to press biscuits down into liquid. You want the top pieces to soak up liquid or they will bake up dry. Let sit 20 minutes.
Bake in a 350 degree oven for 45 minutes.
In a small saucepan, bring butter, 1/2 cup dark browned sugar, 1/4 cup heavy cream, and 1/2 teaspoon vanilla to a simmer. Whisk for 3 to 5 minutes, or until thickened. Let cool slightly before drizzling on bread pudding.
Notes
Store leftovers in refrigerator and reheat before serving.