Preheat your oven to 350?F / 180?C / gas mark 4. Grease a 9x13 inch cake pan with butter or non-stick cooking spray.

In a medium bowl, whisk together the cake flour, baking powder, and pink pitaya powder.

In a large mixing bowl, beat together the butter, sugar, and oil until creamy and light in color, about 3 minutes.

Add the eggs, one at a time, and continue mixing until well combined. Scrape down the sides of the bowl.

With the mixer on low speed, mix half of the dry ingredients into the batter until mostly incorporated. Then, stir in the buttermilk and rosewater and mix until well combined. Mix in the remaining dry ingredients until smooth.

Pour the batter into the prepared cake pan and spread it out evenly.

Bake the cake for 30 to 35 minutes, until a toothpick comes out with just a few crumbs.

Remove the cake from the oven and use the end of a wooden spoon to poke holes all over the cake.

In a liquid measuring cup, stir together the condensed milk and rose water.

Pour the condensed milk mixture evenly over the warm cake and let it soak into the holes. It's fine if a little remains on top.

Allow the cake to cool completely inside the baking pan.

Once cooled, place the cold heavy cream, powdered sugar, and rosewater into a large mixing bowl. Beat at high speed until stiff peaks form.

Spread the whipped topping over the cold cake. Decorate with dried rose buds or small fresh roses.

Refrigerate until ready to serve. Cut the cake into 12 to 15 slices.