Partially bake a pie crust. To do so, line the pie shell with foil and then weigh down with ceramic pie weights or dry beans. Bake 10 minutes. Then, take the foil & weights or beans out and bake an additional 5 minutes.
Turn down the oven to 350F.
Prick the sweet potatoes several times with a fork or knife and place them on a double layer of paper towels in the microwave. Cook for 5 minutes; turn each potato over and continue cooking until tender but not mushy- about 5 minutes longer. Cut the potatoes in half and scoop out the flesh out with a spoon. Place it in a medium bowl. You should have 2 cups of sweet potatoes. While they are still hot, add butter and mash with a fork or potato masher. It is okay to still have a few small lumps of potato remaining.
Whisk together the eggs, yolks, granulated sugar, brown sugar, nutmeg, cinnamon, rum, molasses, and salt. Then whisk in the milk. Slowly add the egg mixture to the sweet potatoes, whisk to combine.
Pour the sweet potato mixture into the pie shell.
Cover the edges of the pie shell with foil to prevent over browning. Place the pie on a rimmed
baking sheet. Bake for about 35-40 minutes or until mostly set. (The pie is done when the enter
wiggles slightly when shaken.
While the pie is baking mix together the brown sugar, self rising flour, cinnamon and melted
butter for the streusel and pecans. Top the pie with streusel and bake 5 minutes more or until streusel is browned.