Mix butter, sour cream and flour with the dough hooks of the hand mixer to a smooth dough. Cover and chill for about 2 hours. Divide dough into 4 parts. Mix lime zest, brown and white sugar with coconut flakes. Sprinkle 1/4 of it on the work surface. Roll out one piece of dough on top of it round (approx. 26 cm Ø).
Divide into 16 pieces with a cake divider (alternatively, use a knife to divide into about 16 pieces). Process the rest of the dough in the same way. Roll up the cake pieces into croissants, starting on the broad side and rolling up to the top. Place the tip downwards on 2 baking trays lined with baking paper. Bake the trays one after the other in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas. level 2) for approx. 12 minutes
2 hours waiting time