Duck egg baking

So I will admit to taking the easy way out.

I baked 2 batches of brownie mix brownies. Both baked in a glass pan, put in a cold oven and baked at 325 for 1hour.

verdict.

The chicken egg batch was its usual gooey brownie goodness. Even the next day (which is as long as they last around here).

The duck egg batch was firmer, dense and chewy. And, superior in satisfaction.

I think I need to test with another, from scratch, recipe - Just to make sure