Slow Cooker Apple Crisp

INGREDIENTS

• 1 cup all-purpose flour
• 1/2 cup light brown sugar
• 1/2 cup white sugar
• 1/2 teaspoon ground cinnamon
• 1/4 teaspoon ground nutmeg
• 1 pinch salt
• 1/2 cup butter, cut into pieces
• 1 cup chopped walnuts
• 1/3 cup white sugar, or to taste
• 1 tablespoon cornstarch
• 1/2 teaspoon ground ginger
• 6 cups apples - peeled, cored and chopped
• 2 tablespoons lemon juice