Clean, peel, and cut 2 to 3 large sweet potatoes into large chunks. Place them in a large pot, cover with water, and bring to a boil over high heat. Cook until fork-tender, approximately 10 minutes.
Drain the water from the pot and mash the sweet potatoes using a potato masher.
Preheat the oven to 325°F. Grease and lightly flour a Bundt or tube pan, then set it aside.
Whisk together 3 cups all-purpose flour, 1/2 teaspoon salt, 2 teaspoons baking powder, 1 teaspoon baking soda, 1/2 teaspoon ground nutmeg, and 1 teaspoon ground cinnamon in a small bowl.
Cream 1 cup butter and 2 cups granulated sugar in a large bowl or stand mixer using a hand mixer on medium speed.
Add 2 1/2 cups mashed sweet potatoes to the mixer and beat until the batter is light and fluffy. Incorporate 4 large eggs one at a time, mixing well after each addition.
Gradually add the dry ingredients until well combined, then stir in 1 teaspoon vanilla extract and 1/2 teaspoon lemon extract.
Pour the batter into the prepared pan and bake at 325°F for 1 hour and 10 minutes, or until golden brown and a cake tester comes out clean.
Remove the cake from the oven and let it rest in the pan on a wire rack for at least 10 minutes. Invert the cake onto a serving plate, remove the pan, and allow it to cool completely before slicing.
Prepare a glaze by mixing 1 cup powdered sugar with 3 tablespoons orange or lemon juice, then drizzle it over the cooled cake.
