01 - Preheat oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or lightly grease each cup.
02 - In a large mixing bowl, whisk together 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 cohesive.
04 - Pour the wet mixture into the dry ingredients. Gently stir with a spatula until just combined, avoiding overmixing.
05 - Stir in white chocolate chips until evenly distributed throughout the batter.
06 - Divide batter equally among muffin cups, filling each one approximately three-quarters full.
07 - Bake for 20 to 22 minutes or until a toothpick inserted in the center of a muffin emerges clean.
08 - Allow muffins to cool in the pan for 5 minutes. Transfer to a wire rack to cool completely before serving.