Cut the top off of a pie pumpkin.

Cut the pumpkin into two halves.

Scrape out the seeds and stringy part of the inside of the pumpkin.

Set the seeds aside in a cup or bowl.

Pour water into a large pot, half-full.

Add the two pumpkin halves to the water and heat to boiling.

Boil approximately 20 minutes (or until pumpkin is soft when cut through with a knife).

Scoop out the pumpkin into a bowl and cool at room temperature.

Discard the outer part of the pumpkin.

Preheat oven to 350°F.

Grease a 9x13-inch glass pan.

Add flour, baking powder, baking soda, salt, cinnamon, nutmeg, and cloves in a bowl and whisk together, then set aside.

Mix the vegetable oil, eggs, brown sugar, granulated sugar, cooled pumpkin, and vanilla extract in a separate bowl.

Add the vegetable oil mixture to the dry ingredients and mix together until smooth.

Pour into the greased baking dish, and bake for 30-35 minutes.

Test it at 30 minutes by putting a toothpick in the center of the cake.

If the toothpick looks clean, the cake is done.

Cool the cake on a hot pad or trivet.

Soften butter in the microwave by using the defrost method.

Add the vanilla extract.

Mix in the powdered sugar with a hand mixer on low (carefully so that the sugar doesn't scatter everywhere) a little at a time.

Beat at medium to high speed for 2 minutes after the butter, vanilla, and powdered sugar are mixed well.

Spread the frosting onto the cooled pumpkin cake.

The cake is easier to slice when it has set for an hour or more in the fridge.

But if you can't wait, go ahead and enjoy a piece of warm pumpkin spice cake freshly topped with butter frosting.