Mountain Berry Crumb Pie

INGREDIENTS

2 1/2 cups

all purpose flour ((10.6 ounces), plus more for rolling)

2 tbsp

sugar

3/4 tsp

salt

1/2 cup

cold butter (, diced)

4 tbsp

shortening

to 9 tablespoons water

1 tbsp

white vinegar

beaten egg to brush the pie shell

3 lb

frozen mixed berries ((strawberries, blueberries, raspberries, and blackberries), defrosted and drained very well)

1/3 cup

cornstarch

small lemon (, juiced and zested)

1/2

to 3/4 cup sugar

1/2 tsp

salt

1/4 tsp

cinnamon

1/4 cup

butter (, diced)

1/2 cup

oatmeal ((not instant))

1/2 cup

all purpose flour

1/2 cup

brown sugar

1/2 tsp

cinnamon