Preheat oven to 325. Lightly grease or spray donut pan and set aside.
In a small bowl, microwave the butter and Biscoff until melted, about 15 to 20 seconds.
In a large bowl, mix together flour and the remaining ingredients until combined. Add the melted Biscoff mixture and stir to combine.
Carefully fill donut cavites about two-thirds full, using a piping bag or a cookie scoop. Bake for 8-11 minutes, until donuts spring back when touched. These took 9 minutes in my oven. Allow to cool for approximately 5 minutes before removing from pan.
For the glaze:
In a small bowl, melt the butter and Biscoff. Add the powdered sugar and vanilla and stir. Slowly add milk, one tablespoon at a time, until desired consistency is reached. Dip the donuts into the glaze, and eat!
Recipe by Kitchen Meets Girl at https://kitchenmeetsgirl.com/chocolate-biscoff-donuts-with-vanilla-biscoff-glaze/