1-First things first, set your oven to 425°F and line 9 muffin tins with paper cups to avoid any sticking. Cream the butter and sugar for about 3 minutes until it's light and fluffy this step really helps the muffins rise well and gives that tender texture.

2-Next, add the egg and beat for another minute, then mix in the Greek yogurt and vanilla extract for that moist, filling quality. In a separate bowl, combine the flour, baking powder, baking soda, and salt.

3-Gradually add the dry ingredients to the wet mixture and stir until just combined, then fold in the chocolate chunks carefully to keep those gooey melts intact. Spoon the batter evenly into the muffin tins, filling them nearly to the top, and sprinkle a bit of extra granulated sugar on each for a sweet crunch.

4-Bake for 5 minutes at 425°F, then lower the temperature to 375°F and bake for an additional 15 minutes until the muffins are golden brown and springy to the touch. Let them cool for at least 5 minutes before serving these steps take about 10 minutes prep and 20 minutes baking, totaling around 30 minutes.

5-First Step: Preheat your oven to 375°F (190°C). Line a muffin tin with paper liners or grease it lightly to prevent sticking.

6-Second Step: In a large bowl, whisk together the all-purpose flour, baking powder, baking soda, sugar, and salt until evenly combined.

7-Third Step: In a separate bowl, mix the milk, vegetable oil, and egg until smooth. For vegan variations, substitute with plant-based milk and flax egg.

8-Fourth Step: Pour the wet ingredients into the dry and gently fold them together, being careful not to overmix. The batter should be lumpy.

9-Fifth Step: Fold in the chocolate chunks evenly throughout the batter.

10-Sixth Step: Spoon the batter into the muffin tins, filling each about 2/3 full.

11-Seventh Step: Bake for 18-22 minutes, or until a toothpick inserted into the center comes out clean or with moist crumbs.

12-Eighth Step: Remove from oven and let the muffins cool in the pan for 5 minutes before transferring to a wire rack.

13-Final Step: Serve warm or at room temperature. Store leftovers appropriately. For gluten-free adaptations, ensure all ingredients are certified gluten-free for safety.