It was predawn at the Mercado de Coyoacán. Pastel storefronts. Light streaming out of the market aisles in ribbons onto the dark sidewalk. And quiet—a refreshing, almost unnerving experience for Mexico City. We had come to make fajitas—puntas de la Veracruzana—with Adriana Luna, who runs La Cocina de Mi Mamá at the back of the market. She has a broad 100-watt smile.

The restaurant is modern and well equipped in contrast to the many market restaurants that are more higgledy-piggledy with propane burners and makeshift work- spaces. Behind the restaurant, which has wooden tables and a lunch counter, was an impressive bar with dozens of beer varieties and full service, a great place to end the day. But it was still morning before the market was open: chilly with just a hint of the hustle and bustle to come.

As Luna prepped and we set up for the shoot, she served large coffees and slices of corn cake— panqué de elote—dusted with powdered sugar with a sprig of rosemary upstanding. It didn’t look like cornbread. It was fluffier, lighter and more cake-like, if the cake were more devil’s food than layer cake.

The first bite was a game-changer. It was only slightly sweet, moist and nothing like cornbread, which is denser and cornier. On the second and third bites, it was the texture that really took hold—softer and more velvety than cake. Bite after bite, I couldn’t quite size up the flavor, which was more whisper than declaration. A hint of corn flavor, but less than you expect and a suggestion of sweetness without being sweet. I finished two pieces and could have easily tucked into a third.

Luna introduced me to her baker, who revealed two key facts: The only sugar came in the form of sweetened condensed milk and the batter was made entirely in a blender. The ingredient list was short: grated corn, milk, sweetened condensed milk, eggs, flour, butter and baking powder. No bowl needed.

Back at Milk Street, we ran into problems. Turns out Mexican corn is starchier and less sweet than American varieties, which meant we were not getting the texture we wanted. It was too sweet and too dense. After a half dozen variations—we even tried frozen corn (the results were gummy) and cornmeal instead of fresh corn—we still were stumped. The texture was elusive.

Finally, after another half dozen cakes, we ended up with something pretty close to the original by way of adding cornmeal, cornstarch and yogurt, but keeping the grated fresh corn and the sweetened condensed milk. We also substituted oil for butter, which produces moister cakes (think carrot cake). The first part of the recipe was made in a blender, but then we folded the dry ingredients into the liquid ingredients in a bowl for best texture.

At home, I have made this recipe many times. The last piece always is eaten within 24 hours—the ultimate test for this simple homemade cake.