Combine milk and lemon grass in a small saucepan over medium heat and heat until almost boiling, or about 180*F. Let sit for 20 min.

Preheat oven to 350*F and line a muffin tin with cupcake liners.

Strain tea from milk and combine with butter, yogurt, sugar, and lime zest. Whisk until sugar dissolves fully.

In a large mixing bowl combine and sift flour, baking soda, baking powder, and salt. Pour wet ingredients over dry and mix just until comes together, allowing small lumps to remain. A balloon whisk works best for this. Immediately pour into cupcake liners and bake for 20-22 min., or until a toothpick inserted into to center comes out clean.

Meanwhile, fold crystallized ginger into the creme fraiche and return to the refrigerator.

When cupcakes are done, remove from oven and allow to cool. After 5 min. remove from muffin tin to cooling rack and allow to cool completely before topping with creme mixture. Top each cupcake with approximately a scant tbsp. of creme and then serve immediately. Garnish with extra ginger or lime zest if desired.