INGREDIENTS
1/3 cup
all-purpose flour
1/2 tsp
baking powder
1 cup
powdered sugar (, plus more for dusting)
salt
3
large eggs
1 cup
half and half
1 1/2 tsp
vanilla extract
1 tsp
butter (, for greasing the baking pan)
1 tbsp
granulated sugar (, for dusting the baking pan)
6 oz
blackberries
6 oz
blueberries
Lemon zest of half a lemon (, optional)