Can we take food across the US/Canada border on our road trip to Niagara Falls?

Hi Angie,
Whether your point of entry is at the border crossing or airport, the rules are the same, you must declare all food, plants, animals, and their by-products. This is a direct quote from the Canadian Food Inspection Agency: Travellers are required, by law, to declare all plant, animal, and food items they bring into Canada. This includes items related to plants, animals and food, or their by-products.
For more information, you can call the Border Information Service (BIS) at 204-983-3500 or 506-636-5064 from the US. Select 0 to talk to a person (not a machine).

Canadian rules about importing food for personal use from the US:
http://inspection.gc.ca/food/information-for-consumers/travellers/what-can-i-bring-into-canada-/eng/1389648337546/1389648516990
US rules about importing food for personal use from Canada:
https://help.cbp.gov/app/answers/detail/a_id/1273/~/food--bring-personal-use-food-into-the-u.s.-from-canada