Once batter has had a few minutes to sit, scoop about 1/4 cup of batter into each greased ring and cook at a medium-low temperature to ensure that the batter cooks through. When bubbles have risen and broken on the top and it starts to look a little dry on top around the sides, gently lift the edge to see if it is a golden brown. If it is ready to flip, sprinkle a little of the crumble mixture onto the raw side of the pancake and then flip and continue cooking until the other side is brown and the pancake is cooked through.