• Heat oven to 425ºF (218C). Poke sweet potato all over with fork. Roast until soft, 45–80 minutes (depending on size). Remove and let cool. Reduce oven to 350ºF (176ºC).

Cake

• Meanwhile, whisk together ¾ cup brown sugar, 2 eggs, ½ cup oil, 3 tablespoons milk, 1 tablespoon pumpkin pie spice until smooth.
  
• Stir in 1 ¼ cups (207g) flour until completely combined. Cover and refrigerate while sweet potato cooks.
  
• Spray bottom and sides of a 9-inch round (or 8-inch square) baking pan with nonstick cooking spray. Cut a round of parchment paper to size of pan and lay flat in bottom of pan.

Streusel

• Mix butter, ⅓ cup sugar, ⅓ cup flour, 1 ¼ teaspoons spice, and ¼ teaspoon salt until crumble and chunky.
  

Purée

• Peel cooked sweet potato, add flesh to a mini food processor and process until smooth. (You can also mash by hand using a potato masher. Make sure you mash it until completely smooth.)
  
• Add 1 cup sweet potato puree (222g), remaining ¼ cup flour (31g), 1 teaspoon baking powder, ½ teaspoon baking soda and ½ teaspoon kosher salt to batter; mix to combine.
  
• Transfer batter to prepared pan, smooth top and sprinkle streusel evenly over top.
  
• Bake cake until puffed and golden, and a toothpick inserted in center comes out clean, about 40 minutes. Cook cake in pan, on wire rack, for 15 minutes. Carefully remove cake and allow to cool completely on wire rack.
  

Glaze

• In a medium bowl, whisk together ¼ cup cream cheese, 2 tablespoons confectioners’ sugar, pinch of salt and 1 tablespoon milk until smooth. Add additional milk, by teaspoon, until glaze is drizzle yet forms a ribbon in bowl.
• Drizzle glaze over cake and enjoy.