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Preheat oven to 350 degrees F. Line 1 1/2 muffin tins with paper liners. Set aside.
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In a medium bowl, combine all topping ingredients, using a fork or pastry cutter, until mixture looks like coarse crumbs and hold when pressed together. Set aside.
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In another medium bowl, combine flour, baking powder, baking soda, salt, and cinnamon.
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In a large bowl, beat together butter and sugar until pale and fluffy, about 2 minutes. Add vanilla, sour cream, and one egg. Mix until combined; add remaining egg and mix until combined. Add flour mixture to butter mixture in two additions; mix until just combined after each addition, scraping the bowl as needed. Batter with be on the thick side and a little sticky.
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Remove 1 cup of batter to a small bowl. Mix in 3 tablespoons creamy Biscoff spread to 1 cup batter until combined; set aside.
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Portion batter among muffin tins, filling each cup 1/2 way full of regular batter. Add a dollop of Biscoff batter to each cup and swirl - each muffin tin should be about 2/3 full now. Generously sprinkle each cup with crumb topping. (If you didn't fill all of the paper liners, remove the extras before baking.)
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Bake for 22 to 25 minutes or until tops begin to brown and a toothpick inserted in the center comes out clean. Remove pans to cool on a wire rack. After 5 minutes remove muffins to wire rack and cool completely.