Mix glutinous rice flour with water to make a dough.
Steam the dough for 20 minutes to make injeolmi rice cake.
Coat the injeolmi thoroughly with roasted soybean flour.
Combine flour, butter, sugar, and salt to make streusel dough.
Crumble the streusel dough into small pieces.
Top the injeolmi with streusel crumbs.
Bake in a 180°C oven for 10 minutes to finish.