Preheat the oven to 425°F and prepare the baking tin by lining or greasing it
In a mixing bowl, whisk together the melted butter, oil and sugar until well combined
Add the eggs and whisk for 2-3 minutes or until pale in color
Add the milk mixture, vanilla extract, and sour cream, then mix until well combined
In a separate bowl, combine the dry ingredients: flour, baking powder, baking soda, and salt. Reserve 2 tablespoons of the dry mixture to coat the strawberries
Pour the wet mixture into the dry ingredients and mix until just combined
Toss the strawberries in the reserved 2 tablespoons of dry mixture and add to the batter along with white chocolate chips. Do not overmix
Let the batter sit at room temperature for 30 minutes without mixing
Divide the batter evenly among the muffin cups
Bake for 5 minutes, then reduce the oven temperature to 375°F without opening the oven door
Continue baking for an additional 15 minutes or until a toothpick inserted in the center comes out clean
Allow the muffins to cool in the tin for 5 minutes before transferring to a wire rack to cool completely
