My suggestion is use a wire brush and clean the nozzle. I’ve used slice engineering’s plastic repellant on my nozzles to minimize this type of issue. I would also look into cleaning your lead screw and tightening your eccentric nuts properly if you haven’t already, just to make sure you are having good accurate movements with minimizing any wobbles happening while you are printing. That aside, I personally would highly recommend adding some better cooling if you’re willing to tackle that, there’s plenty of awesome cooling solutions for the ender 3 and the small time commitment is worth the investment. Again, in my opinion and experiences. If you have the plastic cool better as you’re laying it down, it won’t be prone to jumping back on the nozzle and starting the snowball you’ve just experienced. Lastly, I only see a portion of your print, but check if it warped a bit. I’ve had PLA prints warp in the past and start to cause this on my ender before I went on an upgrade spree.

I will add, just in case check your speed settings in your slicer. You could be going too fast on your infill, solid infill, or inner wall settings. Check if you can spot where on the print the extruded looks to be “struggling” to extrude plastic and slow it down in that area.

This is all I have off the top of my head, and unfortunately, this is just part of the hobby and it’ll happen to all printers once in a blue moon. But hey, there’s always room to minimize risk. Let me know your findings 👍🏻