Combine the cornstarch and powdered sugar in a small bowl. Line an 8-inch square baking pan with parchment paper with wings coming up a few inches off the sides. Spray it with cooking spray, then dust it with half of the cornstarch mixture. Set the pan and the rest of the mixture aside.
Combine the honey, 1 2/3 cups granulated sugar and 1 3/4 cups water in a large saucepan fitted with a candy thermometer and stir to combine. Place over medium-high heat and cook until the mixture reaches 305 degrees F.
Meanwhile, position a stand mixer fitted with the whisk attachment near the stove. Place the egg whites and salt in the bowl of the mixer.
Beat the egg whites until stiff peaks form. Reduce the speed to medium and beat in the remaining tablespoon granulated sugar. (Do this while keeping an eye on the honey so you don't burn it.)
As soon as the honey reaches 305 degrees F, turn the mixer speed to medium-low and add it to the egg whites in a steady drizzle. Then turn the mixer to high and beat until pale and fluffy, 3 to 5 minutes.
Remove the bowl from the stand mixer and spray a rubber spatula with cooking spray. Add the nuts to the mixture and fold with the sprayed spatula to combine. Scrape the mixture into the prepared pan. Press it into an even layer, then sprinkle on the remaining cornstarch mixture and let cool, a few hours. Use the parchment wings to remove the nougat to a board. Cut the nougat into 1-inch squares.
Set up a sheet pan with a rack and set aside.
Heat the semisweet chocolate with 1/2 tablespoon oil in a double boiler or in a heatproof bowl in the microwave in 30-second increments, stirring after each, until melted, 1 1/2 minutes total. Repeat with the ruby chips and remaining 1/2 tablespoon oil. Brushing off the excess powdered sugar from the top of each, dip half of the squares in the regular chocolate and half in the ruby chocolate, spooning some over the tops so that they are completely covered. Use a fork to remove the squares from the chocolate and place on the prepared rack. Sprinkle with sprinkles, if using. Refrigerate until the chocolate is set, about 10 minutes, or let set at room temperature for about 20 minutes. Serve at room temperature.