Quickly muddle the raspberries and the ice in a shaker tin to break the raspberries up, try not to break the ice too much as this will cause it to melt. Add the rest of the ingredients to the shaker tin (except the garnish, of course) and shake vigorously for 15 seconds to combine. Dump the entire contents into a bucket glass (or whatever suits your fancy) and add ice as needed. Garnish with orange slice and remaining raspberries. Serve immediately, and again, sip slowly.
Notes
Muddling the raspberries into a pulp and then adding a tablespoon to the cocktail can make this drink much faster to assemble and save your ice from getting crushed.
If you let this drink sit for a while the ice melts with float on top because the liquors are heavy. Give it a quick stir and the flavors will be balanced again. You can also dump it back in the shaker tin and then into the cup again and it will mix nicely together.
* You do not have to use essential oils but if you do make sure you use essential oils that are food-grade and safe for internal consumption.