I made this recipe last weekend and while it came out very tasty, there was the occasional gritty texture/crunch similar to sand at the beach getting in your mouth. This was more of an issue since the recipe produces a more cake-like cookie, so the grit stands out more.
The batter was pretty thick and difficult to stir, but it seemed fairly well mixed. I have a feeling this is somehow related to the baking powder/soda, but not entirely sure.
SAJ14SAJ mentioned the creaming method being a possible source to the issue. I wasn't entirely sure with that step, how exactly would you "cream together" sugar and butter? It said only to soften and not melt, and it definitely didn't appear "creamy" when I was done with it.