The first time I made this Biscoff banana pudding I used four bananas instead of five, and I was annoyed about it all evening. Petty, I know. But a layered banana pudding lives or dies on whether you hit banana in every spoonful, and four bananas spread across a 9 by 13 pan leaves bald patches. Five covers it.

Everything else about this one is forgiving. No oven. No stovetop custard, no tempering eggs over a double boiler while you pray. Speculoos cookies stand in for vanilla wafers, and cookie butter goes straight into the whipped cream. That spiced caramel edge does something to banana that plain vanilla never quite manages. It reads closer to brown butter than to a cookie.

Seven hours start to finish. About thirty minutes of that is you actually working.

The pudding has to set before anything else happens

This is the step people skip, and it decides whether you get clean layers or a dish of sweet slush.

Sweetened condensed milk, whole milk, and a large box of instant vanilla pudding powder get whisked together and go into the fridge for three hours. That ratio is heavier than what the pudding box tells you to do. On purpose. The condensed milk brings sugar and milk solids the box ratio does not, so the base sets denser and firmer, and it can carry three cups of whipped cream folded through it without going loose.

Make it the box way and the pudding tastes fine on its own. Then you fold in the cream, build the pan, and somewhere around hour two in the fridge the whole thing has quietly slid toward one side of the dish. Ask me how I know.

Three hours is the floor. Overnight is better, if you are the kind of person who plans dessert a day ahead. I usually am not.

What to buy, and the two things that actually matter

Most of this list is uncomplicated. Two items are worth reading about.

The pudding mix has to be instant, not cook-and-serve. They sit next to each other on the shelf in nearly identical boxes and they behave nothing alike. Cook-and-serve will not thicken cold, no matter how long you leave it.

The cream has to be heavy whipping cream, the kind at 36 percent fat or above. Cartons labeled only “whipping cream” run closer to 30 percent. They will whip. They also deflate faster, and by day two the pudding weeps a thin puddle at the bottom of the dish.

For the rest: smooth cookie butter, not crunchy, since you are whisking it into cream and you want it to disappear completely. Warm it ten or fifteen seconds in the microwave before you drizzle and no longer, or it thins out and runs straight down through the layers instead of sitting where you put it.

Bananas want to be yellow with a few freckles. Green ones taste like starch and stay firm. Heavily spotted ones go to mush between the layers and turn the cream around them a dull grey.

Powdered sugar rather than granulated in the cream, because the cornstarch in it helps the whip hold its shape. A quarter cup is not very sweet. That is deliberate, since the cookie butter and the condensed milk are already carrying more than enough sugar between them.

Building the layers

Whip the cream and powdered sugar to soft peaks. Soft, not stiff. Stiff peaks look impressive in the bowl and then break when you fold the pudding in, and broken whipped cream is grainy and there is no fixing it.

Add half a cup of cookie butter to the whipped cream and beat just until the color is even with no streaks running through it. It goes from white to a pale tan. Then fold the chilled pudding base into that cream. Fold, do not beat. You are trying to keep the air you just spent four minutes building.

Now the pan. Start with cream on the bottom, a thin layer, enough to keep the first row of cookies from gluing themselves to the dish. Then cookies, laid flat and pushed close together. Then a generous layer of cream over the top of them. Two sliced bananas across that, then a drizzle of the warmed cookie butter.

Repeat the whole sequence. Cookies, cream, bananas, drizzle. Finish with one last layer of cookies and one last layer of cream over the top.

You will almost certainly have cream left over. That is intentional. Running short on the top layer is a worse problem than having a container of extra in the fridge. It keeps about three days and is good with strawberries, or stirred into iced matcha, which sounds strange and is not.

Finish the top with the rest of the cookie butter and a handful of crushed cookies. Hold the sliced banana for the top until just before you serve.

Cover and refrigerate three to four hours at minimum.

Things I got wrong the first few times

Bananas on top will brown within an hour or two, whatever you do. Lemon juice slows it down and also makes the top taste like lemon, so I gave up and started slicing them at the table instead.

The bananas inside do not brown, because they are sealed between cream layers with no air reaching them. This surprises people every time.

Serve it with a large spoon rather than trying to cut squares. Nothing structural is holding this together, and lifting a neat portion out of the pan mostly just compresses it into a puck.

It keeps three days covered in the fridge. Day two is better than day one, which is rare for anything with banana in it. By day three the cookies have gone completely soft and cake-like. Some people prefer that. Some people consider it a failure. I am in the first group.

If you need it firmer for travel, add an extra half cup of crushed cookies as the bottom layer and give it the full overnight chill instead of four hours.

Serves 12, generously.