Dont get xp from cooking
You have to get into the higher level recipes for XP. My level 76 Elementalist was getting xp all through the different levels of cooking, but less so on ones that had light yellow text. Orange text (in the recipe name) gave much better xp and I actually went up two levels from 74.
You’ll only get xp, when you discovery new recipes, or craft recipes that are GreenishBlue, or Gold. If they are white, you are wasting resources (if your not actively using that item) as you get zero experience. I would focus on only making items that are GOLD in xp, and if you dont have them, then go to a site such as : http://www.gw2db.com/recipes/cook and discover some of the items at the level 25 range you are missing.
Best of luck.