Hi, thanks a lot for your message :)
In Level 2, you don't have a oven in the beginning, the only way is to buy a oven once you reach the shop ( level 5 ). Then if you replay level 2 ( or the other levels ) you'll have the oven you bought
There's only a oven cars in the 2 special stages by default.
For he recipe cards, they just tell you how to make a recipe, and in the left panel ( if you check the left side of the screen there should be a little arrow button ) you'll be able to see again the discovered recipes.
You can then sell the recipe cards
Also, I could not fix before releasing that version, but normally once you find a recipe once, you don't loot it again ( as it would become quickly annoying 😅 )
I hope it answers your questions, and thanks again for the feedback :)