Easiest Triple Berry Crumble (made with frozen fruit!)

INGREDIENTS

4 cups

frozen mixed berries*, NOT thawed (about 24 ounces frozen fruit)

3 tbsp

granulated sugar

3 tbsp

all purpose flour

zest from 1 lemon

salt

1 cup

old fashioned rolled oats

1/2 cup

brown sugar

6 tbsp

all purpose flour

1 stick

salted butter, cold, cut into small cubes