The sweet treats are listed in the phase 1 "foods to enjoy" list:
viewtopic.php?t=29305It's linked to from the Phase 1 FAQ - if you haven't read that, you should look it over.
My guess is that, as a vegan, your two challenges in phase 1 will be getting enough protein and good carbs. Soy products such as tofu are fine as protein sources, and you can have lowfat soy milk or soy yogurt (without starch) too. Other vegetarians/vegans also rely on beans and other legumes. And be sure to get your daily serving of nuts/seeds in.
The other challenge is getting enough good carbs, to keep your energy up and keep ketosis away. Be sure to eat beans or other legumes, and try to include some of the higher-carb phase 1 vegetables such as tomatoes and onions. A calorie guide is helpful here, since most of the calories in vegetables come from carbohydrates. The higher-calorie vegetables are likely to be better sources of good carbs. Very low-calorie vegetables like lettuce and leafy greens may not help as much. (BTW all phase 1 vegetables except legumes are low in calories - it's just that some aren't quite as low.) But remember, stick with the phase 1 vegetables (see the "foods to enjoy" list).