
Most often, people will have two or more favorite vlas: with a selection of over twenty flavors, it is easy to find several that you like. The most common flavors are of course vanilla and chocolate, but others like caramel, blanke vla (with a flavor that nobody has yet been able to define, it is simply called "white vla" or "blank vla", depending on how you interpret it), lemon, raspberry...you name it. Seasonal vlas include stoofpeertjes vla, or apple/cinnamon for the fall, and lighter ones, mixed with yogurt for the summer or spring.
But vla has always been one of those desserts that I didn't want to try and make at home: after all, how can you approach the flavor that has been carefully (and chemically) defined in dairy factories all over the country? Newer cookbooks don't mention vla anymore, but digging deep into the early and mid last century cookbooks brought up a few recipes. And I am so glad I did: it turned out to be much easier than I expected and definitely an improvement over any store-bought vlas!
Vla is, as far as I can tell, a typical Dutch dessert, and seemingly one of "recent" discovery. The cookbook of the Haagsche Kookschool from 1895 does not mention any vla: the closest recipe is one for vanilla sauce, but another cookbook, the Nieuw Praktisch Kookboek, first published in 1906 gives recipes for chocolate vla, vanilla vla and even almond vla. Hurray, the vla has been invented!!

Hopjesvla
1/2 cup sugar
2 cups milk
1/2 cup strong, black coffee
2 teaspoons instant coffee (optional)
3 tablespoons corn starch
2 egg yolks
Heat a saucepan with a heavy bottom and add the sugar. Watch carefully as the dry sugar turns liquid and slowly colors golden. Monitor your heat carefully as sugar will go quickly from golden to burnt!
Mix the coffee with the milk and stir well to dissolve the instant coffee granules. When the sugar has caramelized CAREFULLY pour half of the milk in the pan. The sugar will seize up and harden, but by stirring and bringing the milk up to a slow boil, the caramel will soften and eventually dissolve. Continue to stir.

The vla will thicken in the next two to three minutes, and will be ready to take off the stove when it "gloops" i.e. air bubbles will come to the surface and instead of disappearing will leave small holes in the vla, making a "gloop" sound. That's the best I can describe it!
Pour the vla in a bowl, cover with plastic film to avoid the formation of a milk skin, and refrigerate until cold.
To achieve the pourable consistency, you may need to add a tablespoon or two of cold milk to the vla and stir it well before serving.