For the Streusel:

• 3 cups all-purpose flour (spooned and leveled)
• 1 cup brown sugar (packed)
• 1/2 cup granulated sugar
• 1 teaspoon kosher salt
• 1 tablespoon cinnamon
• 1 tablespoon pumpkin pie spice
• 1 cup butter (2 sticks, melted)

For the Cake:

• 2 1/4 cups all-purpose flour
• 1 1/2 cups granulated sugar
• 1 tablespoon baking powder
• 3/4 teaspoon baking soda
• 3/4 teaspoon kosher salt
• 1 tablespoon pumpkin pie spice
• 1 teaspoon cinnamon
• 1/2 cup butter (1 stick, softened but still cool)
• 1 15-oz can pumpkin puree (not pumpkin pie filling), divided
• 4 large eggs
• 1/4 cup vegetable oil (light-flavor olive oil works well)
• 1 tablespoon vanilla extract

For the Icing:

• 1/4 cup butter (1/2 stick, very soft)
• 1 teaspoon vanilla extract
• 1/2 teaspoon kosher salt (use less if table salt)
• 3 tablespoons milk (more if needed)
• 2 cups powdered sugar