Heat oven to 375 F. Grease muffin cups or use foil or paper baking cups. Finely chop the ginger. Finely grate the lemon peel so you have 2 tablespoons.
In a large bowl, beat butter and the 1 cup sugar with a wooden spoon or electric mixer until pale and fluffy. Beat in eggs, one at a time. Add ginger and lemon peel.
Stir baking soda into yogurt or buttermilk; it will start to bubble and rise up.
Fold flour into ginger mixture one third at a time, alternating with the yogurt. When well blended, scoop into muffin cups. Bake 18 to 20 minutes, or until lightly browned and springy to the touch.
While muffins bake, mix lemon juice and the 2 tablespoons sugar in a small dish. Stir until sugar dissolves.
When muffins are baked, remove from oven and let cool 3 to 5 minutes in pan. Remove from pan and dip top and bottom into lemon juice and sugar mixture.
Note: If you have a food processor use this method: Peel one lemon with a vegetable peeler. Put ginger, lemon peel, and the 1 cup sugar into the food processor, fitted with a steel blade. Process 1 to 2 minutes, scraping sides once, until lemon peel and giner are very finely chopped. Add butter; process about 30 seconds until creamy. Add eggs, one at a time, processing briefly after each addition. Scrape mixture into a large bowl; if it looks curdled, don't worry. Add baking soda, yogurt, and flour and continue as above.
Source: Muffins By Elizabeth Alston