Preheat oven to 350 degrees.
Spray a half sheet cake pan (11x15) with non-stick cooking spray. Set aside.
In a large bowl, combine eggs, sugar, oil and pumpkin at medium speed with electric mixer until fluffy.
In medium bowl whisk together flour, cinnamon, baking powder, baking soda and salt.
Add dry ingredients to wet ingredients at low speed until well combined.
Spread batter into prepared pan.
Bake for 25-30 minutes until toothpick comes out clean when inserted in middle of cake.
Let cool before frosting.
In bowl of stand mixer combine butter, sugar, cinnamon and salt. Beat on low speed until blended, about one minute.
Add the vanilla and cream and increase speed to medium and continue to beat for 4 minutes until smooth and creamy.
Add more cream, if necessary, for good spreading consistency.
Lightly frost the top of the cake.
Cut into small squares and place on serving tray.
Pipe a rose on top of each square.