Prepare a boiling water bath canner and four half pint jars.

Pit and chop the plums. Core and chop the pears. Make sure to cut away any soft spots.

Place the chopped fruit into a low, wide pan and measure honey into the fruit. The easiest way to do that is to pop the pan onto a digital scale, press the zero/tare button, and then measure out 8 ounces of honey.

Give the fruit a good stir to help combine the honey and add the lemon juice and cinnamon.

Set the pot on the stove over high heat and bring the fruit to a boil.

Cook, stirring regularly, until the jam thickens. Reduce the heat a bit if it becomes splashy.

When you like the consistency of the jam, remove the pot from the heat.

Funnel the finished jam into the prepared jars. Wipe the rims, apply the lids and rings, and process in a boiling water bath canner for 10 minutes.