Preheat your oven to 350°F (175°C) and line a muffin tin with paper liners or grease it with cooking spray.
In a large mixing bowl, whisk together the all-purpose flour, whole wheat flour, sugar, baking powder, baking soda, and salt until well combined.
In another bowl, mix the Greek yogurt, eggs, vegetable oil, and vanilla extract until smooth and creamy.
Pour the wet ingredients into the dry ingredients and gently fold them together using a spatula until just combined. Be careful not to overmix; it’s okay if there are a few lumps.
Add in the chocolate chips and nuts (if using) and fold gently until evenly distributed.
Divide the batter evenly among the muffin cups, filling each about 3/4 full.
Bake in the preheated oven for 15-18 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
Allow the muffins to cool in the tin for 5 minutes before transferring them to a wire rack to cool completely.
Notes
Serve warm or at room temperature, dusted with powdered sugar.