Which logical fallacy is used in the text?
Quinoa is a delicious, plant-based source of protein because it tastes so darn good.

 - circular reasoning: an argument that supports a claim with the claim itself
 - ad hominem: a personal attack against one's opponent
The text argues that quinoa is delicious because it tastes good. However, the "evidence" is just a restatement of the claim itself. This illustrates a type of logical fallacy known as circular reasoning.