Preheat oven to 425 degrees.
Spray 20-cavity donut pans with cooking spray.
Set aside.
In a large mixing bowl, whisk flour, baking powder, baking soda, salt and granulated sugar.
Set aside.
In a medium sized mixing bowl, whisk the milk, sour cream and eggs until smooth.
Whisk in pumpkin, vanilla extract and pumpkin pie spice.
Pour the pumpkin mixture into the flour mixture.
Add Heath English Toffee Bits.
Stir just until combined.
Do not overmix.
Batter will be very thick.
Spoon batter into a large zip-lock bag.
Trim a corner off the bottom of the bag and pipe batter into each donut cavity.
Fill each cup 3∕4 full.
Bake for 10 minutes at 425 degrees or until the edges are lightly browned, and a toothpick inserted in center comes out clean.
Remove pan from oven and cool approximately 2 minutes on a cooling rack.
Remove donuts from the pan and place on cooling rack.
Dip baked donuts in glaze.
Place donuts on cooling rack and immediately sprinkle about ½ teaspoon Heath English Toffee Bits evenly over each donut.
Do one donut at a time.
Otherwise glaze will dry too fast and Heath English Toffee Bits will not adhere to the glaze.
Allow donuts to rest on cooling rack approximately 10 minutes until icing sets.
Serve.