Beat the butter and sugar till fluffy. Add egg and vanilla. Beat till well incorporated.
Add coconut, millet flour and plain flour. Mix well. You will end up with a moist dough. Sprinkle the coarse sugar all over evenly and just mix it once.
Cover and refrigerate for at least 1 hour.
Preheat the oven to 180 C for at least 15 mins.
Make balls and flatten them slightly on the baking sheet.
Bake these till done. Takes around 10 mins for me. When done the cookies top is dry.
You can make ragi cookies in batches till you use up the entire dough.
Store ragi cookies in a air tight jar.