Place egg yolks in a medium bowl and beat about 1 1/2 to 2 minutes with a hand mixer (or stand mixer) until yolks are creamy, pale yellow, and doubled in volume.
While beater is on, sprinkle 2/3 cups sugar over egg yolks and beat until combined.
Cut vanilla bean in half and scrape out seeds inside with the back of a knife.
Place vanilla seeds and beanstalks plus milk, cream, ground almonds and canela stick in a medium saucepan.
Slowly bring to a gentle boil over low heat, stirring often.
Remove from heat once gentle boil has been reached.
Temper 1/4 cup of hot milk into yolk mixture one tablespoon at a time, taking care to whisk yolks while adding hot liquid.
Add tempered yolk mixture to milk mixture slowly; constantly mix milk during this process.
Return to heat over a low flame and heat until mixture reaches 160˚F on a candy thermometer or until it thickly coats the back of a wooden spoon.
Remove from heat; place in refrigerator for 4 hours or overnight to cool.
Remove from refrigerator, strain out vanilla bean stalks and discard. Add rum and mix well.
In a large bowl, whisk room temperature egg whites with a hand mixer (or stand mixer) until they have tripled in volume and you have soft peaks. This will take 2 to 2 1/2 minutes depending on hand mixer.
Sprinkle remaining 1 tablespoon sugar over egg whites and continue to beat until they form stiff peaks.
Gently fold egg whites into milk mixture with a spatula, making sure all lumps are mixed in.
Serve immediately with a dusting of ground almonds.