01 - Preheat oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or lightly grease each cavity.
02 - In a large mixing bowl, whisk together the all-purpose flour, matcha powder, baking powder, baking soda, salt, and ground cinnamon until thoroughly blended.
03 - In a separate bowl, whisk pumpkin puree, granulated sugar, packed brown sugar, eggs, vegetable oil, milk, and vanilla extract until the mixture is smooth and uniform.
04 - Pour the wet mixture into the bowl of dry ingredients. Stir gently with a spatula until just incorporated, ensuring you do not overmix the batter.
05 - Gently fold white chocolate chips into the batter until evenly distributed.
06 - Spoon the mixture evenly into the prepared muffin tin, filling each cup approximately three-quarters full.
07 - Transfer the tin to the oven and bake for 20 to 22 minutes, or until a toothpick inserted into the center of a muffin emerges clean.
08 - Allow muffins to cool in the pan for 5 minutes, then move them onto a wire rack to cool completely before serving.