1. Preheat oven to 350ºF. Grease 24 mini muffin cups or insert paper liners.
2. Sift together flour, baking powder, salt and spices. In a large bowl, using an electric mixer, cream butter and brown sugar until fluffy. Beat in egg, oil, milk and pumpkin puree until well mixed. Stir in dry ingredients just until combined; do not overmix. Divide batter among cups, sprinkle each with a few pumpkin seeds and bake until a toothpick inserted in center of a muffin comes out clean, 15 to 17 minutes. Let cool in pan on a rack for 5 minutes, then turn out and let cool completely.