Caramel Through Thick and Thin: Bravetart's Alfajores Con Cajeta

I have never used goat's milk in a recipe (or for anything) before, so I was interested in trying Stella Parks' recipe for Alfajores, which include a homemade Cajeta, or goat's milk caramel. And the recipe looked pretty straightforward, so I wasn't anticipating any problems.

To make the cajeta, you simply cook ultra-high-temperature pasteurized goat's milk (I was able to find Meyenberg milk, Stella's recommend brand, at both Whole Foods and Yes! Organic) with a scraped Mexican vanilla bean pod, sugar, baking soda, and salt, until you have a thick caramel. This process takes some time and requires constant stirring, but I set a stool in front of the stove and just parked myself there for the duration. There is no target temperature provided, but Stella says the cajeta is done when a trail left behind from scraping a spatula across the bottom of the pot stays open for one second. I removed the vanilla bean pod, let the cajeta cool, and stored it in a glass jar in the fridge.

The cookie portion of the alfajores is just a vanilla shortbread. You make the dough in the food processor by blending flour, vanilla bean seeds, tapioca starch, powdered sugar, salt, baking powder, cold butter, and egg yolks. The recipe instructs you to roll the dough out to a thickness just shy of 1/4-inch, and says that you should be able to cut 50 two-inch cookies from a batch of dough. I rolled the dough to a quarter-inch and was baffled by how little dough there was. (To give you an idea of the scale of the recipe, there is less than one cup of flour in the dough, and only one stick of butter.) I rolled the dough to 1/8-inch thick and was able to cut 44 two-inch diameter cookies. They were done baking in only 10 minutes.
I had made the cajeta a day in advance (Stella says you can keep it refrigerated for three months), and when I pulled it out of the fridge to fill the cookies, it was a solid block. I had to stick the jar of cajeta in a pan of very hot water and wait for it to soften sufficiently to be able to scoop it (if we owned a microwave, I would have used that instead). I wasn't happy with the way the cookies came out. As you can see in the photo above, the cookies were quite thin, and I has been too stingy with the cajeta (my fault -- I did have cajeta left over).

I decided to give the recipe another try. I made a double batch of cajeta, and this time I stopped cooking it a little earlier, so it wasn't as thick as my first batch. For some reason, however, the second batch of cajeta was a rich mahogany color that was darker than my first attempt. I also made a double batch of cookies (it makes sense to match the amount of cajeta to the amount of cookie dough, because the cajeta requires one vanilla pod, and one batch of dough requires the seeds scraped from one vanilla pod) and rolled the dough thicker, to 3/16th of an inch. I was able to get 62 two-inch diameter cookies from my double batch of dough, and they took 14 minutes to bake.
I was really optimistic about my thicker cookies and my thinner cajeta. Until I started assembling the cookies. The cajeta was stiff but scoopable straight out of the fridge, and it seemed thick enough that it would be able to hold its shape. But as I started filling cookies and setting them on the counter, I noticed cajeta seeping out of the cookies. I wasn't planning to roll the edges of the cookies in dried coconut, but I did it as a desperate measure, hoping that the coconut would help contain the caramel. It didn't. As you can see in the photo above, the cajeta escaped from the cookies, with the coconut failing to keep it in check. I just ended up with coconut-coated caramel everywhere.

I kept the cookies in the fridge after assembly, and the problem with the runny cajeta only got worse as the cookies warmed up. I took the photo above immediately after taking the cookies out of the fridge. I brought the cookies to the office and as they sat out at room temperature, the cajeta continued to leak out, to the point where all of the cookies were just sitting in a contiguous puddle of caramel. It was pretty ridiculous. I guess I have yet to find the sweet spot for the cajeta, but I think that the right thickness cookie with the right thickness cajeta would be really good.  And I think that for a two-inch diameter cookie, a thickness of 3/16th inch seems just right.

The cookie is slightly crumbly, such that when you bite into the cookie it gives way cleanly. The cajeta has a lovely caramel flavor, and you can definitely taste the difference from the goat's milk -- it is slightly funky, but in a good way. And I did really like the texture from the coconut, so I would probably add it even if my caramel was under control. I found this whole experience a bit frustrating, so I'm not planning to return to this recipe anytime soon... But eventually, I want to get the right caramel with the right cookie.

Recipes: "Alfajores Con Cajeta" and "Cajeta Casera" by Stella Parks.