My friend Usha has a method for creating personalized cake experiences. It’s usually a birthday cake, or a cake for some other event in which a specific person (or couple) is honored. Each cake is decadent in its own way, a sweet and creamy reflection of the honoree. After viewing her cakes on Facebook, my 4-year-old son wanted one for his birthday.

Usha lives in Hawaii, where we happened to have been planning a trip. She and Remy corresponded about the flavors in what I call the “interview phase” of Usha’s cake experience.

Here, a baseline palate of flavors is established, while any additional goals the honoree may have, for the cake itself or for the event it headlines, are explored. When those variables are addressed, she then adds the appropriate cake, custards and frostings.

As he would be in Hawaii, Remy went with a tropical fruit theme. Mango and liliquoi (“lily-quoy”) aka passion fruit.

Mango season had just passed in Hawaii, but farmy folk like Usha have freezerbags full of frozen mango filets, among other frozen tropical delicacies.

But if her freezer was bare it wouldn’t matter. Usha can bake a cake anywhere, with whatever cake-able ingredients she can sniff out. Apples in Vermont, salmon berries in the Cascades, strawberries in Santa Cruz, huckleberries in the Palouse. With her process you can do the same.

Her only hard and fast rule is no money. There will be no reimbursement or compensation of any type, be it barter, subway tokens or clam shells, nor will any discussion of cost be tolerated. The gift of cake exists outside of time, occasion, place, and the economy.

The only ingredient in Remy’s cake that can be scarce on the mainland is fresh passion fruit. Mangos are always in season somewhere and can easily be found frozen, but fresh liliqoi is rare outside of places where people know how to use it. It looks pretty bad when perfectly ripe, and the edible part consists of sour goop with seeds stuck inside. It needs to be strained and sweetened, and takes work to eat. If you can get ripe liliquoi or a suitable concentrate, by all means make this cake. Otherwise lemon, per the original recipe, works lovely.

There is just one more thing you will need if you want to make Remy’s cake. A copy of a certain book that Usha acquired in Portland in the years since the last time I’d watched her bake.

The book was written by my first boss, Judy Rosenberg, founder of Rosie’s Bakery in Somerville, Mass. Never before has a cookbook been so perfectly relevant to Usha’s interest than Rosie’s Bakery All-Butter Fresh Cream Sugar-Packed No-Holds-Barred Baking Book.

My retail position at Rosie’s during the summer after my sophomore years was my first job ever. Rosie’s was legendary in the Boston area, largely on the back of a frosted brownie called the Chocolate Orgasm. My first day on the job was the morning after my first hickey.

I never met Judy, but I remember her presence, and the gravitas her name carried, not to mention the fact that her last name could remain unspoken. Then, 30 years later, I saw her name on the book that Usha won at a law school party 20 years ago. Four different recipes from the Rosie’s All-Butter book, modified with local fruit, combine to make Remy’s birthday cake.

When we arrived, Usha was making lemon custard (page 88), but with liliquoi juice ice cubes instead of lemon juice. Sweetened and creamed, the sour liliquoi creates a cantilevered, balanced flavor that is thrilling to consume. She could have just stopped right there, as far as I was concerned, but Usha was just getting started.

Using the recipe for Banana Cake (page 56), she measured out a cup of chopped mango instead, and soaked the pieces in “…a cup plus 2 tablespoons” worth of buttermilk.

You know a recipe is serious when it gives quantities like, “a cup plus two tablespoons.”

Remy worked the mango pieces hard into the buttermilk with his bare hands. “I’m crushing it,” he remarked.

During the course of that afternoon at Usha’s, she and Remy decided to add some pineapple from the freezer, from last summer’s harvest. They minced and stirred the pieces into a bowl of vanilla custard Usha had prepared earlier, just in case (page 87). Then Remy reminded Usha they had at one point discussed cinnamon.

“Most of these cakes take like three days to make,” observed Usha’s sweetheart Bill. “Evenings, mornings,” she said, cheerfully.

It was time to start baking. Remy greased the pan with butter, then lay a circular piece of parchment paper over the butter on the bottom, then more butter, smearing in the parchment paper like a layer of paper mache. Then Usha added some flower to each pan, rolling it around for total coverage, before spooning in the batter. That cake would not be sticking to any pan.

These recipes, as noted, aren’t for novices. If you don’t have a cake mixer, you’ll need elbow grease. The Rosie’s Buttercream frosting (page 85), took about five minutes in a food processor, followed by 20 minutes in a Kitchenaid mixer until in looked like lacquered taffy. Remy gave the mixer a deep cleaning with his tongue.

The buttermilk mango cake batter, meanwhile, had mixed relatively quickly, with cinnamon from the tree next to Usha’s yurt.

After about 20 minutes at 350 (preheated, center rack), she took the cakes from the oven and palpated them, absorbing information through her fingertips. She was trying to grok the situation at the cake’s core, noting the degree to which the skin bounced back after being pushed upon. She was looking for a near-but-not-quite-total recovery.

“You want it to spring back maybe 90 percent,” she estimated. If you’re at a loss, she added, insert a knife or toothpick to test if it’s done.

When personalizing a cake, the list of extra considerations is potentially long, beyond mere allergies and sensitivities and intolerances. Like, how do you get the cake where it needs to be. Most honorees don’t ask to help bake the cake, like Remy, and have it delivered to their event.

“I often travel with my cakes,” Usha says. On the Kona coast that can mean lots of curves and G-forces and bumps, so she prefers to deliver them in pieces, and recommends having other people in the car to hold the cakes.

Other considerations include should the cakes be sliced in half along their horizontal planes, multiplying the surface areas from two discs into four, in order to allow more alternating layers of vanilla pineapple custard and liliquoi custards? (Yes.) And, should there be a school of gummy fish swimming on the buttercream frosting? (Yes.)

And that, in a nutshell, is Usha’s cake method.

When the night is done, Usha brings home all her gear, her bowls of frosting and custard, and her application tools, and everything else, with one exception. The pie pan to which the leftovers are plastered is the one dish that the birthday [boy] was allowed to wash. Other than the mixing bowl and spoon, of course.