Here's the birthday cake, AKA "Rose Petal Cake".
It's a whipped cream cake from the 1948 edition of The Joy of Cooking. No butter, the egg whites are folded into the whipped cream, and then the dry ingredients are very slowly folded into that. I flavored it with rose extract and rose water.
The icing is uncooked icing--sifted powdered sugar worked into butter flavored with rose water. I added a few specks of red jell coloring. The rose petals are from Knock Out roses I planted three years ago.
It's quite easy to make sugared rose petals. I used powdered gum arabic and rosewater to paint them, and let them dry overnight.
The cake was baked in a ring pan, and I put the fresh roses in at the last moment.
(Happy Belated Birthday to me: that's one great thing about baking your own birthday cakes--you get just what you want!)