Claire Ptak first learned about Meghan Markle through Ms. Markle’s former lifestyle blog, The Tig, a so-called hub for the discerning palette that she started in 2014.
After Ms. Ptak, the owner of Violet, a cafe and bakery in London, published “The Violet Bakery Cookbook” in 2015, she sent a copy to Ms. Markle, who later asked to interview her.
“Great questions,” Ms. Ptak, 48, said of that conversation.
Ms. Ptak had by then been living in London for about a decade.
Last year, Ms. Ptak made a version of the cake for a birthday party for the couple’s daughter, Princess Lilibet Diana.