Cook sweet potatoes in oven at 425 degrees for 45-50 minutes until fork can be inserted easily OR for 15 minutes on high pressure with a natural release in the Instant Pot
Preheat oven to 350 degrees
Peel potatoes, put them in a stand mixer and whip for about 30 seconds
Add 1 C brown sugar, 1/2 C milk, 3 eggs, vanilla and 1/2 tsp nutmeg and cinnamon then mix until well incorporated and smooth
Transfer to a greased 9×9 or 9×13 inch baking dish
Bake uncovered for 30 minutes at 350 degrees
In another bowl, combine 3/4 C brown sugar, 1/2 C pecans and 1/4 C flour. Cut in the 2 T butter until crumbly. Sprinkle over baked potatoes and return to oven to cook another 15 minutes.