Pre heat oven to 170℃.
Prepare the cake tin. Grease it with oil or butter and dust it with flour. Set aside.
In a separate bowl, combine the butter and brown sugar. Cream both until light and fluffy with an electric mixer on medium speed (see Note 1). Scrape the sides and bottom of the bowl half way through.
Next, beat in the eggs into the creamed mixture, one at a time (see Note 2). Each time, beat until all the traces of the eggs are no longer visible but do not overbeat. Scrape the sides and bottom of the bowl again to ensure all ingredients are well mixed.
Add the pumpkin puree and beat until it is well combined into the creamed mixture (see Note 3).
In a separate medium bowl, measure the flour, baking powder, salt and the pumpkin spices. Mix them with a hand whisk and sift into the creamed mixture. Fold with a spatula until all traces of the flour is no longer visible (see Note 4). Scrape the sides and bottom of the bowl to ensure the ingredients are well combined and the batter is smooth. Do not over mix.
Transfer the cake batter into the prepared tin and level the top. Bake the cake in the preheated oven for 45 to 50 minutes (until a skewer inserted in the center comes out without any wet batter sticking to it) (see Note 5).
Remove the cake from the oven and let it cool in the tin for a few minutes before turning it out onto a wire rack to cool completely.
Keep the cake covered with a kitchen towel as it cools down. Wrap with a plastic wrap and refrigerate as soon as it cools down to room temperature to lock its moisture. Keep the cake refrigerated until it has cooled down completely.
To make the cream cheese frosting, measure the cream cheese and butter into a mixing bowl. Cream until they are well combined, smooth and creamy (see Note 6).
Next, sift in the powdered sugar. Mix lightly with a spatula to moisten the sugar before using the electric mixer to whip it. This will avoid the sugar from flying all over.
Add the vanilla extract and mix again until well combined.
To frost the cake, place it on a cake board or cake plate. Cover the cake with the frosting evenly but no necessarily smooth. Use a spoon to makes wavy texture on the frosting all over.
Divide the remaining frosting into 3 bowls with 2 of the bowls having slightly more frosting than the third one. Tint the first 2 bowls of frosting with orange and yellow food coloring. Tint the frosting in the third bowl in green. Transfer the frosting into one piping bag each.
Pipe a row of orange stars (orange pumpkins) on the cake with tip #865 followed by yellow stars (yellow pumpkins) using the same tip. For each of the pumpkins, add a small green stem in green icing using star tip #16.
Using the same green icing, pipe tiny tendrils with round tip #2, followed by leaves with tip #67.
To make the smaller piped pumpkins in orange and yellow, use star tip #21. Top each star with a tiny green dot as stems for the pumpkins in green with round tip #2.
Finally, add more leaves in green to complete the decoration.