I start by roasting sweet potatoes until soft, then mashing them into a smooth purée. Meanwhile, I brown the butter over medium heat, letting it get a nutty aroma, then cool it slightly before adding to the batter. This step gives the muffins a rich, deep flavor that’s irresistible.
I mix cream cheese with a little granulated sugar and vanilla until smooth and creamy. This filling becomes the gooey center of each muffin, balancing the sweet, spiced muffin perfectly.
I whisk the dry ingredients, then fold in the wet ingredients including sweet potato purée and brown butter. I spoon half the batter into muffin cups, add a dollop of cream cheese filling, then top with remaining batter and streusel.
I bake the muffins until a toothpick inserted near the edge comes out clean, usually 18–22 minutes for regular size. Cooling on a rack ensures the cream cheese filling sets without tearing.