Blackberry and White Chocolate Layer Cake

INGREDIENTS

2 tsp

1 lemon, juice from

6 cups

Blackberries, fresh

Eggs, large

2 cups

Blackberry jam or preserves

1/4 cup

All-purpose flour

2 tsp

Baking powder

1 tsp

Baking soda

2 1/4 cups

Cake flour

1/4 cup

Cornstarch

1 5/8 tsp

Salt

3 1/4 cups

Sugar

4 tsp

Vanilla, pure

2 tbsp

Vegetable shortening

20 oz

White chocolate, finely chopped or 10 ounce white chocolate chip

Baking spray

Vanilla rolled wafer cookies

4 sticks

Butter, unsalted

1/2 cup

Heavy cream

2 1/4 cups

Milk

1 tablespoon finely grated zest and 3/4 cup juice from 6 to 8 lemons