Caipirinha Donuts

Name: Caipirinha Donuts
Prep time: 40 min
Cook time: 1 h 15 min
Total time: 1 h 55 min
Cuisine: American, Latin American
Ingredients: 1 tbs (golden) flaxseed, ground; 3 tbs water; 120 ml (1/2 cup) soy milk; 1 tbs lime juice; 160 g (1 cup) white flour - spelt or wheat; 80 g (1/3 cup) sugar; 1 1/2 tsp baking powder; 1/4 tsp salt; the zest of 1 lime, ground; 60 ml (1/4 cup) neutral tasting oil; some margarine for the donut mold; 250 g ( 1 1/2 - 2 cups) powdered sugar; 3 tbs Cachaça; 6 thin lime slices; sugar; zest of 1/2 lime