Preheat oven to 350°F. Grease and flour a muffin pan or line with paper liners.
In a large bowl, whisk together the brown sugar, vegetable oil, mashed banana, vanilla extract, and milk. In a separate bowl, combine the flour, whole wheat flour, salt, and baking powder. Add dry ingredients to the wet ingredients and fold until incorporated. Fold in strawberries and pecans.
In a small bowl, stir together the cinnamon, brown sugar, and pecans to make the topping. Fill the muffin pan cups ⅔ full and sprinkle with the topping. Bake until golden brown, about 15 minutes. Let cool slightly before removing muffins from the pan to cool completely.
Calories: 202kcal, Carbohydrates: 30g, Protein: 2g, Fat: 9g, Saturated Fat: 5g, Cholesterol: 1mg, Sodium: 105mg, Potassium: 181mg, Fiber: 1g, Sugar: 18g, Vitamin A: 15IU, Vitamin C: 8mg, Calcium: 55mg, Iron: 1mg