If using honey, preheat your oven to 325 °F (167 °C). If not using honey (which bakes quicker than sugar, hence the lower temperature), preheat to 350 °F (175 °C).
Line 2 round 8" cake pans with parchment paper on the bottom and then grease the sides of the pans.
In a large bowl, stir together the sugar (if using honey, don’t add it yet), flour, cocoa, baking powder, baking soda and salt.
Add eggs, milk, honey (if using), olive oil and vanilla. Mix for 2 minutes on medium and then stir in the boiling water. The batter will be almost as thin as water. If you taste it, it will NOT taste good! But don't worry. It tastes great after baking.
Divide the batter between the two pans.
Bake for 25-30 minutes or until a toothpick comes out with some moist crumbs, but no uncooked liquid. The bake time will vary widely depending on what combination of sugar / eggs / flour you use. The whole wheat / egg / honey version is on the longer side. The gluten-free / chia egg / honey version is on the shorter side.
Let cool completely before frosting.