To me that is a difficult question.
It depends what it is that I ate in terms of how fast the carbs are digested. For example, the fat in the peanut butter is likely to slow down the absorption.
And then I would need to test a lot to find out my peak; if I waited until I next ate (4 - 5 hours later), I would miss the peak.
For some a CGM or the Libre may show this but they are not accurate enough especially at extremes of high or low.
If you find you are staying at the peak, that suggests you have not taken enough insulin.
Maybe your insulin to carb ratio is a bit low or the protein is affecting your insulin needs.