Need help trying to find a book on coffee baking recipes from the 1990s

Hi. My dad has developed dementia, and he used to make me this incredibly delicious flourless chocolate espresso cake, with confectioner's sugar and toasted hazelnuts on top. The recipe was contained in a book that had a purple cover. I remember it being a square-shaped book, with perhaps a mokka pot on the cover. It was published in the early 1990s. I once found it on Amazon, but lost it in a hurricane. I don't remember the name of the book nor the name of the recipe; I've been searching for hours online. I need help. It's my father's birthday today, and I would like to make him this cake in his honor. I appreciate any ideas or leads. Thank you so much.