Preheat oven to 350 degrees and grease a loaf pan. (I use a 9x5).
In a large bowl, beat together the eggs, both sugars, vanilla, pumpkin, and oil.
In the same bowl, sprinkle in the flour, pumpkin spice, cinnamon, baking soda, baking powder, and salt. Mix together with a spatula or hand mixer just until combined.
Add the batter to the greased loaf pan. (If you are not making the streusel topping, you can skip to the baking step now.)
To make the Streusel Topping:
Add all of the ingredients to a medium size bowl and use either a fork, or a pastry cutter, and cut the butter into the mixture until it resembles pea-sized crumbs. Sprinkle over the pumpkin batter.
Bake at 350 for about 1 hour and 15 minutes. To check if the bread is done, insert a toothpick or cake-tester in to the center and it should come out clean.
After baking, let the cake cool for 30 minutes. Then run a knife around the inside edges of the pan before flipping onto a wire rack or plate to finish cooling. Once it's cool enough to handle, you can slice it and serve!