I’m a baker for years. For some reason, I am getting black specks in my cake. A little on the hard size. Mine batter is perfect. What is causing th

Take a look at this thread:
https://www.cakecentral.com/forum/t/630293/tiny-bitter-brown-specks-in-cake
In it, the commentators suspect old or not fully incorporated baking powder. They suggest sifting the baking powder with a fine sieve.

It could be weebles. Did you check the date or sift the flour before using it?

Have been following this mystery with interest.
The bitter taste surprises me - doesn't sound like it would come from any of your regular ingredients.
But the baking spray to prepare the pan may be a problem. I stopped using it years ago because of what I remember as a chemical taste. Could that be similar to what you are describing as bitter?
Have you tried one version with either olive oil or butter to grease the pans? Side by side comparison, one of those with baking spray?
If you do, I'd love to hear the results.

Thanks everyone. I’m going to use my brand new pans the end of the week. I will post my results. Definitely not critters, I tasted it very bitter. Did the vanilla test the first cake that had the flecks.

Try pouring out half a teaspoon of the vanilla on an old pillowcase or very fine paper towel. Come back in a little while and see if you can see tiny flecks.

Take a cup of flour, pour it out on a flat surface, then pour yourself a good bourbon. Sit and watch it intently while you sip your cocktail for any small crawly things that may be turning black as the incinerate in the oven.

Examing the pans with a magnifying glass for imperfections in the pan.

If the flecks are on the bottom and sides, it's probably the pan. If the flecks are uniformly interspersed throughout the batter, it's one of the ingredients.

I am going to try my new pans this week and use my hand mixer. I already threw a bottle of vanilla thinking it was coming from it.

I wonder if it's flecks of vanilla bean in your new bottle of vanilla? Or see if you maybe bought vanilla paste or crushed vanilla rather than straight vanilla extract.

It sounds like it might be the pans. Maybe you could line your pans with buttered/floured parchment paper .... that might help. Try different (new) pans?

New pans. Fresh ingredients, the batter is perfect when it goes in the pan. Thought it might be my vanilla, just bought a brand new bottle.

Could it be the finish coming off the cake pans? Critters in the flour?

Those are the only things I can think of.

??