Can the marcona almonds be skin on?

The only marconas I've used have been roasted with oil and salt. The ones you have might be raw, in which case you could roast them yourself in the oven.

I'd vote for skins off in a perfect world. I've actually never seen marconas with the skins on. They sell them skinless at whole foods.

I've made this recipe and I think that would be just fine!