Citrus, smoke, tea, bitter chocolate-orange.

Brown butter washed rum: Use a decent panamian rum (eg Panama Pacific 9 year). Brown 2 sticks of unsalted butter on stove top. Add butter and rum to a container. Allow container to sit at room temperature for 2 hours. Place container in freezer overnight. Break up fat solids and strain mixture through fine mesh strainer and coffee filter until clear.

Cinnamon simple syrup is 1:1 sugar to water, steeped with a few cinnamon sticks.

I originally used Bacardi 1909 Superior Heritage for this, which is 89 proof. That was a limited edition release and I believe no longer available, so use another higher proof white rum (such as Diplomatico Planas) if available.
For the coffee syrup, I mixed equal parts Aeropress coffee (between a French press and espresso in strength) with demerara sugar.

Danger suggests Tristar strawberries.

The result is a lot more ethereal and closer to a Daiquiri than the classic Painkiller.

I was inspired by Don's Mix (grapefruit + cinnamon) and how well Campari works with cinnamon as well as grapefruit. The 3/8 oz measurements might seem odd, but the concept was to create a grapefruit-Campari-cinnamon syrup cordial so the drink build would be 1.5, 1.5, 0.5, 1 dash.