Guess I better put my husband in the freezer then. LOL JUST KIDDING JUST KIDDING.

I always take all ingredients out before I start, and then put them away as soon as I use each one.

I did use different measuring spoons this time, and might have been distracted. Also, didn't know to put the nutz in the freezer.

I keep nuts in the freezer to if I don't use them right away. The oils in the nuts can go rancid in them and cause bad taste. I also keep my sesame seeds in the freezer for the same reason. I take everything out and put it away immediately after I have added it to my bowl. I get distracted and have ruined a thing or two also. As for the pan, if it is a coated metal pan it could be becoming porus as someone suggested and the flavors of other foods are staying in the metal. I also do all my baking sweets in glass except my Wilton cake pans, savory roasting in metal, never the two to meet.

Speaking of nuts, they can go rancid due to the oil if not kept frozen/refridgerated. Also, the dry ingredients you used can also get old and lose their uumph after awhile, too. I was at Sam's and their 2 pound bag of pecan halves are over $15 a bag now. They had been under $10 a bag and noticed the price increase about a month ago. The lack of rain really cut the yield from the pecan trees. Never hurts to buy a new pan either. I like the new silocon ones, easier to pop out a cake or baked item.

By chance are you using whole wheat flour?
It too can go rancid when kept too long.

If I read your message correctly, you used a Pyrex(glass?) pan for your second try. Was the first pan metal? Usually when I use glass I reduce the temperature by 25 degrees. I have also had flour be bad when I bought it. Not often, but have had it happen 2 or 3 times in the past 40 years.
Give it one more try paying close attention and with fresh flour. Good luck.

When you said it tasted salty I instantly thought of the time my kids made kool-aid for the first time. They asked if they could make Kool-aid by themselves and I thought they have to learn sometime so I let them mix it up. Next they said mom it tastes funny so I asked if they needed more sugar so they added more. It still tasted funny to them so I asked them to show me how much sugar they put in. Well found out they grabbed the wrong container and added salt instead of sugar. They've made it perfect every time since.

Soda and baking powder come with a date on them, but I always put an "opened" date on them with a marker. They generally have a long shelf life, especially soda, but in your case, I would toss them to be sure. It sounds like too much soda or baking powder (or both) was used, but there can also be a problem if they are not well blended into the mix.

Have a double check that you haven't inadvertently mixed up some of the ingredients you have put in your storage jars.

it would be a good idea to have your oven checked I was having problems like that and fould out my oven was not coming on at the right time to keep the tempature even was able to get a small appliance repairman and have had no problems since