Some of the answers:
1. It could be honey. Check to see if there is a crack outside that bees are coming in and out of. – I’m a beekeeper. This is not impossible, but from what I’m seeing, it would be very unlikely. Honey is stored in comb, and when it is released, bees from far and wide will come to clean it. The way it’s clinging to the ceiling also makes this unlikely to me. But, that said, it is not quite impossible. You’d have to check to see if there is bee traffic in and out of that wall to the outside. I do frequent cutouts — from structures and trees alike — and I just have real trouble imagining that much honey sitting out without frenzied bees all over it.

-I’m an archaeologist and I wonder if this is resin from overgreen wood? But there’s a lot of it.

But most days I wish I was a beekeeper 🙂

-So the location of the brown stuff would be equal to ground level. Through the doorway, there’s a staircase up to the kitchen that is on an outside wall. The house is 100 years old, stucco, and the soil adjacent to this is clay and has tons of roots and stuff growing in it.

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-I’m going to agree with the comments calling this caulk/sealant and marking this as solved! The rest of the cracks and gaps have sealant too, this one just looks like it’s gotten moldy or started to rot. It’s definitely not honey

-I was trying to think of a way to tell if it’s honey without tasting the unknown substance. Honey usually smells like honey, but there is another easy way you could test it.

OP, do you bake or have easy access to yeast? You could mix some of the substance with bottled water (no chlorine) in a disposable cup, shake some yeast in, and see if it foams in 15-20 minutes. That would tell you if whatever this is contains fermentable sugars like honey.

-What is above it? Bathroom? Kitchen? Workshop? Electrical panel?

If you wear nitrile gloves and touch it, what does it feel like? Is it tacky? Or dry?

What part of the world are you in?

– It’s unlikely to be honey. Honey is made by European honey bees and stored in honeycombs. Honeybees sometimes leave their hive boxes to establish a new colony. In building or tree cavities, but you would definitely notice a the bee activity outside.

Could it be tree resin from a particularly resinous beam? The thicker area is brown, but along the beam edge to the right it’s clear.

-Wait! If it’s not sticky, and maybe just soft, it could be Clear silicone caulk. When it gets exposed to lots of moisture the underside of it can mold! Smell a tube and compare the scent ????

-I would agree that it could potentially be tree sap from a beam as I’ve absolutely seen unreasonable amounts of sap pour out of milled and treated lumber; however, in those particular cases the sap would dry rather quickly which was quite apparent. Granted these boards were outside and possibly a different species of wood. The molasses smell could indicate the lumber is maple. This is purely speculation though as the consistency looks a little off. I hope you’re able to find a definitive answer.

-I wonder if those beams are made of Ponderosa pine. I’ve read that they can emit sap that smells like butterscotch or vanilla or some sort of cookie.

-Long shot but maybe cockroach poison that was very liberally applied?

Here’s the video: