User Manual Oster 6640-022–NP1 10-Speed Blender with Plastic Jar, 48 Ounce

Yes you can make cookie butter in your 6640 Oster blender. make sure the blender has enough liquid ensure the blade is spinning.

Do not buy this I would recommend the ninja in bought this it quick working in a month and no it’s not good at crushing anything more than ice I bought a ninja I use it everyday I’ve had it for 3 years now and still going strong and it grinds nuts easily