Preheat oven to 325ºF. Prepare Dimensions Large Pumpkin Pan lightly with vegetable pan spray with flour. Place on baking sheet.
In medium bowl, combine flour, baking powder, cinnamon, salt and nutmeg. In large bowl, beat butter and sugar with electric mixer until light and fluffy. Add eggs, one at a time, mixing well after each addition; beat in vanilla. Add flour mixture alternately with pumpkin; mix well. Pour batter into prepared pan.
Bake 70-80 minutes or until toothpick inserted in center comes out clean. Cool 15 minutes in pan. Turn onto cooling rack. Cool completely before serving.