Grandma Susan's Pumpkin Cake

I have no idea where she got it, but this is how my mom always made her pumpkin cake. I've seen a few similar recipes, but none that quite matched it. Alternate ingredients are suggested for anyone wanting to keep it non-dairy.

• Ready In: 1 hr 20 mins
• Serves: 10

Ingredients

• Crust

• 1 (18 ounce) package  yellow cake mix, minus 1 cup set aside for topping
• 1⁄2 cup margarine or 1⁄2 cup butter, melted
• 1  egg

• Filling

• 2⁄3 cup milk or 2⁄3 cup  non-dairy whipping cream
• 2  eggs
• 3  cups  pumpkin pie mix (un-spiced) or 3  cups canned pumpkin (un-spiced)

• Pumpkin Pie Spices

• 1⁄2 teaspoon cinnamon
• 1⁄2 teaspoon allspice
• 1⁄2 teaspoon clove, ground
• 1⁄2 teaspoon ginger powder
• 1⁄2 cup brown sugar

• Topping

• 1  cup  yellow cake mix, the cup reserved from the crust
• 1⁄2 cup sugar
• 1⁄4 cup margarine or 1⁄4 cup butter

Directions

1. Crust: Combine ingredients and press into a baking pan.
2. Filling: Combine until smooth. If not using pumpkin pie mix (pre-spiced) then add the Pumpkin Pie Spices (pumpkin pie mix already includes it). Pour over the crust.
3. Topping: Combine all ingredients. The cake mix and sugar should be cut into the margarine with a knife, over and over until it is may small fragments almost like buttery crumbs (don't melt the margarine or blend it). Sprinkle over filling.
4. Bake at 175C for 1 hour or longer, until inserted knife comes out clean.
5. Serve with whipped cream ideally.