WHY IS MY PECAN PIE RUNNY?
Using too much of your wet ingredients like corn syrup or butter in the recipe can be a common culprit for runny pecan pie, as well as not baking it long enough. Both of these will lead to a filling that’s not set properly.
The best way to avoid a runny pecan pie is to ensure you are using the correct measurements for all of your ingredients and measuring them accurately. When baking, also make sure you are cooking it long enough — at least 45 to 60 minutes — and checking on it periodically throughout its baking time.
If you have already made runny pecan pie filling, there are still solutions. One option is to thicken up your filling by mixing together a bit of cornstarch and cold water until completely dissolved before stirring into your mixture. Flour or instant pudding mix can also be used if you do not have cornstarch on hand. During baking, the extra starch can help thicken the runny filling.