"What is the recommended dosage?"
You have to remember they are meant to be medicinal. Terra bites are very effective for sleep at night but most people only need 1-3 to induce sleep. (average THC dose needed 5-8mg)
If you are really tempted by them you may want to find an alternative product.
Using only what you need helps keep tolerance down and is the most economical way to use cannabis. Regularly ingesting higher than needed doses of cannabis will increase your tolerance to the products.
Additionally, ingesting more THC than needed can produce unwanted and prolonged dysphoria (psychedelic effects) and high doses of cannabis can cause hyper-emesis (vomiting) in some people who over do it with edibles.
Perhaps that makes eating the whole canister less appealing.
Be well.
drgerhart