In a medium bowl stir together flour, baking powder, cinnamon, baking soda, and salt. Set aside.
In a large bowl beat together eggs, pumpkin, sugar, and oil. Add flour mixture mix well. Spread batter into greased cake pan. Bake at 350 degrees for 20-25 minutes or till toothpick comes out clean. Let cool.
Cream cheese frosting: Beat together cream cheese, butter, and vanilla. Add powder sugar little at a time till you get a creamy frosting. Make sure cake is fully cooled and spread frosting on and serve.