Bake a Dark Matter Drizzler for the Dean of the Aionians. These cosmically delicious confections are composed of Ether Cane and Dark Frosting ingredients and may confound physics, but certainly not the taste buds! The Dean can be found in Caldera on Kepler or in the Caldera Solo Op.
Ether Cane can be gathered by defeating Fallen combatants.
Additional information about ingredient source and usage can be found by viewing the details screen on Eva's Holiday Oven.