Toast the almonds: Preheat the oven to 350?F. Lightly coat a 13" x 18" rimmed baking sheet with cooking spray, and spread the almonds on it in an even layer. Bake, stirring a couple of times with a heatproof spatula or a wooden spoon, until the almonds are golden brown and fragrant, about 10 minutes. Allow the nuts to cool completely on the baking sheet, then transfer them to a medium-sized bowl. Line the baking sheet with parchment paper or a silicone mat.
Combine the sugar, water, and cream of tartar in a small (2-quart) saucepan, and bring to a boil, uncovered, over high heat. Insert a candy thermometer.
Reduce the heat to medium-high and cook the mixture, without stirring, until it reaches 280?F, 8 to 10 minutes. Add the almonds, stir them to coat, and continue to cook, stirring frequently, until the mixture reaches 305?F (hard crack stage) and is brown and fragrant, another 5 to 7 minutes.
Remove the saucepan from the heat. Stir in the oil, mix well to combine, and carefully pour the mixture onto the prepared baking sheet, scraping it out and pressing it into an even layer with the spatula.
Wait a minute or two for the mixture to cool slightly. Then lay a sheet of parchment paper or a silicone mat on top of it and gently press down to even out the layer of almonds. As the mixture cools, CAREFULLY use your fingers to separate the almonds before the sugar sets up and becomes brittle. Allow the caramelized almonds to cool completely, about 30 minutes.
In the meantime, melt the 2 cups chopped chocolate over a double boiler and keep warm, but not hot.
Transfer the almonds back to their bowl, and line the baking sheet again, this time with parchment or wax paper.
Set up your dipping station as follows: Place an empty bowl in front of you; to its left, the bowl of almonds; to its right, the bowl of chocolate and then a small bowl with the confectioner's sugar. Set the lined baking sheet nearby. If you don't want to get your hands messy, feel free to put on non-powdered vinyl or latex food service gloves (available at some drug and grocery stores).
Place a few nuts and a spoonful or two of chocolate in the empty bowl and gently toss the nuts with your hands until they're coated with chocolate. Drop the chocolate-covered nuts in the confectioner's sugar and toss to cover. Repeat this procedure until all the nuts are dipped and dredged, fishing the dredged nuts out of the sugar and placing them on the baking sheet every once in a while as they set up (this makes more room for the next round of nuts). Allow the dragées to set completely, about 10 minutes.
Store the dragées in an airtight container at room temperature for up to 2 weeks.