Preheat oven to 350 degrees. Line 12-cup muffin tin with paper liners or cooking spray; reserve.
Combine flour, 1 Tbl. lemon zest, and baking powder in a medium bowl; reserve.
Place 1/2 cup sugar and crystallized ginger in your Vitamix or food processor container. Starting at the lowest setting, increasing to Variable 3 blend for 5 seconds or until ginger is finely chopped.
Starting at the lowest setting, add 1/3 cup butter to the container, slowly increase to Variable 4 and blend for 10 seconds or until well combined. Stop blending and use a rubber spatula to scrape sides.
Add milk and egg to the container. Begin at the lowest setting, slowly increase to Variable 5 and blend for 15 seconds.
Pour wet mixture into flour mixture and combine by hand until well mixed.
Spoon 1/4 cup into each muffin cup. Mixture will be thick. Bake for 18-20 minutes until toothpick inserted in center comes out clean and edges are lightly browned.
Meanwhile, in a small bowl stir together 1/4 cup sugar and 2 tsp. lemon zest. In a separate small bowl, combine 2 1/2 Tbl. melted butter with lemon juice.
While muffins are still hot, dip the tops into melted butter then into lemon sugar. Cool on wire racks.