Batangan Runtuh Raspberry

Bahan-bahan (12 porsi)

• two 12-ounce bags of frozen raspberries (see notes)
• 1/2 cup granulated sugar (more depending on tartness of your berries)
• 2 tablespoons flour
• 1 tablespoon cornstarch
• juice of one lemon
• 3 cups rolled oats
• 3 cups flour
• 2 cups brown sugar (loosely packed)
• 1 teaspoon baking powder
• 1 1/2 cups melted butter (I prefer salted)
• 1/2 teaspoon salt