Preheat oven:

Set the oven to 400°F (205°C).

Rinse and dry blueberries:

Rinse the blueberries and dry them with a towel; transfer to a small bowl.

Mill fresh flour:

Grind 221.3 g soft white wheat and 94.9 g hard white wheat on a fine mill setting.

Coat blueberries with flour:

Dust 1 tsp of the freshly ground flour over the blueberries and stir to coat; reserve. This step keeps them from sinking.

Mix dry ingredients:

Combine 12.6 g baking powder, 5.7 g salt, and 3 g cinnamon with the leftover flour; stir gently and set aside.

Whisk wet ingredients:

In another bowl, whisk together 1 large egg, 284.6 g milk, 56.6 g olive oil, 7.5 g vanilla extract, and 57 g sugar. Beat with a hand or stand mixer until fully blended.

Combine wet and dry:

Dig a well in the dry mix and gradually stream in the wet mix. Using a dough hook, blend only until everything is moistened—do not overwork. The batter may appear thin or lumpy; refrain from adding extra flour.

Rest the batter:

Wrap the bowl and allow it to rest for 15–20 minutes. The batter will become thicker.

Prepare streusel dry mix:

To prepare the streusel: Mill 80 g soft white wheat berries on a fine setting. Stir together with 80 g powdered sugar, 0.6 g cinnamon, and a pinch of salt.

Add melted butter to streusel:

Melt 70 g unsalted butter and incorporate it into the streusel dry mixture until well combined.

Let streusel absorb butter:

Let the streusel sit for 10–15 minutes so it can absorb the butter.

Fold in blueberries:

Once the muffin batter has rested, carefully fold in the coated blueberries using a dough hook, being cautious not to overmix.

Fill muffin cups:

Distribute the batter equally among 12 lined baking cups (they should be almost full).

Top with streusel:

If using streusel, break it into crumbs with a fork or your fingers and scatter over the muffins.

Bake muffins:

Bake at 400°F (205°C) for 18–20 minutes, or until the internal temperature reads 200–205°F (93–96°C).