Thaw and chop strawberries:

Thaw the frozen strawberries only until they can be chopped; avoid full thawing to prevent them from becoming too soft and overcooking.

Preheat oven to 400°F:

Set the oven to 400°F (205°C) to preheat.

Prepare muffin pan:

Place cupcake liners in a muffin pan and mist each liner with nonstick cooking spray.

Coat strawberries with flour:

In a small bowl, mix the chopped strawberries with 2 tablespoons of flour until they are evenly coated.

Whisk dry ingredients:

In a large bowl, whisk the remaining flour, sugar, baking powder, cinnamon, and salt together.

Mix wet ingredients:

In a medium bowl, combine the buttermilk, vegetable oil, egg, yogurt, and vanilla extract, whisking until smooth.

Combine wet and dry:

Add the wet mixture to the dry ingredients and stir just until no streaks of flour remain.

Fold in strawberries and chips:

Gently fold in the floured strawberries and 3/4 cup of chocolate chips.

Fill muffin cups:

Fill each muffin cup about three-quarters full with batter, then scatter extra chocolate chips over the tops.

Bake muffins:

Bake for 20 minutes, or until a toothpick inserted into the center of a muffin comes out clean. If needed, continue baking for a few additional minutes.

Cool on wire rack:

Let the muffins cool on a wire rack.