01 - Preheat oven to 375°F. Line a mini muffin tin with paper liners or lightly grease each cup.
02 - In a medium bowl, whisk together the flour, granulated sugar, brown sugar, baking powder, baking soda, and salt until evenly distributed.
03 - In a large bowl, whisk together the vegetable oil, milk, eggs, vanilla extract, and Greek yogurt until smooth and well blended.
04 - Add the dry ingredients to the wet mixture and fold gently until just combined. Do not overmix to keep muffins tender.
05 - Gently fold in mini chocolate chips or blueberries, if using, distributing them evenly throughout the batter.
06 - Spoon the batter evenly into the prepared mini muffin pan, filling each cup about 3/4 full.
07 - Bake for 10 to 12 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
08 - Let the muffins cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.