R. v. Blake-Samuels, 2021 ONCA 77, February 5, 2021, at paragraphs 29 to 33:

There is no dispute that a sentencing judge retains discretion to exceed the Crown’s position on sentencing. What is in issue is the process that must be followed when a sentencing judge wishes to exercise that discretion. This court has not previously had the opportunity to answer this question in the context where a sentencing judge has both failed to provide notice of an intention to exceed the Crown’s proposal on sentence and failed to provide reasons for that decision.

In my view, if a sentencing judge intends to exceed the Crown’s position on sentence, the judge is required to notify counsel, provide an opportunity for further submissions, and provide clear and cogent reasons for imposing a sentence beyond the Crown’s position.

I will deal with the appellant’s issues together as they all bear on one another.

Fundamental fairness requires the parties to be permitted to make further submissions if the sentencing judge intends to exceed the sentence proposed by the Crown and clear and cogent reasons are required if the judge, having heard additional submissions, still believes it necessary to go beyond the Crown’s position.

More than a recommendation that sentencing judges follow this procedure is required. It is not appropriate to deny procedural fairness during the sentencing process with the expectation that any error can be cured on appeal. It is contrary to the commitment to access to justice, contrary to natural justice, and contrary to a commitment to judicial economy to permit sentencing judges to go beyond counsel submissions and force offenders to rely on the appeal process to ensure fairness. Fairness should be afforded at all steps.