Brown Sugar Raspberry Jam Crumble Bars

INGREDIENTS

2 cups

Raspberries, fresh or frozen and defrosted

2 cups

(rolled) oats, old-fashioned

1 1/2 cups

Raspberry jam, good-quality

2 cups

All-purpose flour

1/2 tsp

Baking soda

1 cup

Brown sugar, packed dark

1/4 tsp

Cardamom, ground

1/2 tsp

Cinnamon, ground

2 cups

Granulated sugar

1/2 tsp

Sea salt, fine-grain

1 tbsp

Vanilla extract, pure

1/4 cup

Walnuts

1 cup

Butter, unsalted