Apple Streusel Topping

• 3 tablespoons all-purpose flour
• 1 1/2 tablespoons unsalted butter, cold and cut into cubes
• 1 1/2 tablespoons light brown sugar
• 2 teaspoons granulated sugar
• pinch salt
• 1/4 teaspoon ground cinnamon or pumpkin pie spice
• 1 1/2 tablespoons diced apples reserved from below

Apple Pumpkin Muffins

• 1 1/2 tablespoons full-fat sour cream, room temperature
• 5 tablespoons pure canned pumpkin
• 1 tablespoon apple juice or orange juice or water
• 3 tablespoons granulated sugar
• 2 tablespoons light brown sugar
• 1 large egg yolk, room temperature
• 1/2 teaspoon vanilla extract
• 1/2 cup fresh apple, cut into small cubes
• 1/2 cup plus 1 tablespoon all-purpose flour
• 1/4 teaspoon baking soda
• 1/8 teaspoon salt
• 3/4 teaspoon pumpkin pie spice