Preheat oven to 400 degrees F. Line a 12-cup muffin pan with liners.

Make the streusel first by combining flour, sugar, ground pretzels, broken pretzels and cinnamon. Stir in melted butter, cover and place in the fridge to chill while you make the muffin batter.

For the muffins, combine flour, ground pretzels*, chocolate chips, baking powder, salt and cinnamon. In a separate bowl, whisk together buttermilk, sugar, eggs and oil until fully combined and sugar is dissolved. Add melted butter and vanilla and stir into flour mixture. Let batter rest two minutes before dividing into muffin cups.

Squeeze cold streusel between your fingers into clumps. Top muffins with streusel (okay to pile it high) and sprinkle with fleur de sel. Bake for 20 minutes or until a toothpick comes out clean. Let muffins cool in pan for 10 minutes before removing.

*Pretzels should be ground until very small pieces remain, as per the picture. If they are ground too fine or completely pulverized your muffins could end up dry.

**The added fleur de sel is a nice touch to the pretzel muffin. You could leave it out. The muffins should not be topped with regular salt. While all salt is chemically the same, the size and shape of the grain makes a difference in recipes. Fleur de sel has larger, less dense flakes. This allows for a more perceptible texture, and a longer slower saltiness as it dissolves in the mouth, therefore changing the way it tastes in a recipe. Do not substitute.