Combine all ingredients for the dough in a bowl and let it sit in a warm oven (40 degreess C) for 30 minutes.
Combine white bean paste, powdered strawberry and sugar and mix well.
Do the same for the matcha paste.
Divide dough into four even portions.
Place strawberry paste in the center of the dough and wrap to enclose.
Flatten the dough with your hand.
Make 10 cuts starting from the outside in, making sure to stop cutting before you get to the center.
Slightly twist each cut of dough inwards to create flower petals.
Brush with beaten egg and sprinkle sesame seeds onto the center.
Bake for 15-20 minutes at 180 degrees C.