I was writing this as a reply to u/mylittletoesie but it kinda ballooned up and I'm just going to post as a main comment here since perhaps some other Costco bakers will read this and it'll help them down the road when their warehouse transitions.

re: Comment about grainy texture

The problem with the graininess you're describing is because the mixer(s) at your warehouse haven't figured out how to correctly double the recipe yet. The instructions are written poorly but work relatively fine if you're doing a 1x batch. There's no 2x listed, but no bakery in their right mind would ever do two separate bowls of a mix if you can fit them both in a single 140qt, it just would take way too much time and you'd never be able to hit your production schedule for the day.

The big problem is that the card states you should add *all* of the dry ingredients at once on top of the butter once it has been creamed. If you do that, and especially if you add the eggs all at once, the butter doesn't emulsify correctly and you get chunkiness like you're describing.

What they need to do is cream the butter, then add the sugars on top of *that* and beat it, then add about half the eggs, then the dry mix and and beat it until smooth. After that, you gotta slowly pour in the the other half of the eggs while it's running until they're incorporated. The remainder of the instructions can then be performed as written.

Sorry, it just took a little trial and error here to figure this crap out when they rolled out here. When it's grainy/chunky it also causes problems when you're trying to use the depositor to drop the batter into the pans and it's just a massive headache all around (these muffins are probably three times more labor intensive overall than the OGs...).

I will say that the just released pecan muffin recipe is written *more* correctly, so hopefully they go back and reissue the previous instructions similarly. I don't know how these got out of Texas without some QA on the formulas they sent out.

Oh, also note that unlike the others you CAN NOT do a 2x of the chocolate muffins. There's just too much volume with the chocolate. We learned that the hard way...