Preheat the oven to 350ºF. Line a muffin pan with paper liners or spray with cooking spray. Set aside.
In a medium bowl, whisk together flour, spices, baking soda, and salt. Set aside.
In a large bowl, combine the pumpkin, sugar, oil, eggs, and vanilla. Stir until smooth.
Gradually add the dry ingredients to the pumpkin mixture, and stir until just combined. Stir in the toffee bits and mini chocolate chips.
Divide the batter among lined muffin cups, filling each cup 3/4 full.
To make the streusel, in a small bowl combine the flour, brown sugar, toffee bits, and mini chocolate chips. Cut the butter into the mixture using your fingers until mixture is coarse and crumbly. Sprinkle about a tablespoon of the mixture over each unbaked muffin.
Bake muffins for 18-20 minutes, or until a toothpick stuck in the middle comes out with just a few crumbs. Let cool to room temperature before serving.