I did 1.5 times the recipe, and I wouldn't recommend doing that. The volume fits in the TMX OK, but the machine has trouble mixing it all together at the turning to crumbs stage.
The batter is quite sloppy and I found it difficult to work with getting it into the muffin tins, in that the blueberries and choc chips kept sinking to the bottom, and I had to constantly stir the mixture to get even distribution of the "bits".
Having said that, the muffins are moist, soft, light and fluffy and absolutely delicious!
Taste: 5/5 Ease of making: 3-4/5
Linked JD