Preheat oven to 350 degrees Fahrenheit.

In a large bowl, combine honey, oil, egg, and lemon juice. Mix well.

Add oat bran, flour, baking powder, and yogurt and mix until fully incorporated.

Fold in blueberries.

In a medium-sized bowl, combine sugar with zest and mix with your fingers in order to release the flavors of the zest.

Add flour and oil and mix until crumbly.

Pour muffin batter into muffin tins. Top with crumbs.

Bake for 22–25 minutes, until an inserted toothpick comes out clean and crumbs are slightly golden.