In a large bowl, add the bread flour, cake flour, yeast, brown sugar and salt first.
Then add the milk, yogurt, honey and egg into the bowl and use mixer to whisk on low speed until the mixture forms a dough.
Add the butter and continue to whisk until the dough is smooth.
Cover bowl with plastic wrap and rest the dough aside for 1 hour at room temperature.
After fermentation, add the pearl sugar and use mixer again to mix in pearl sugar for 15 seconds.