Preheat the oven to 350°F. Line a 9 x 13 inch pan with non-stick foil.
Combine the sugars, four and salt in a bowl, stirring to combine.
Add the melted butter, cream, yolks and vanilla. Stir vigorously for 30 seconds to completely combine.
Stir in the pecans and coconut until everything is nicely coated.
Spread the batter in the prepared pan. Spread it right to the edges, and poke it into the corners.
Bake in the preheated oven for 30 minutes, turning the pan around at the 15 minute mark to promote even browning.
Cool the brittle in the pan on a rack to room temperature. While the brittle is cooling, you can sprinkle it with the chocolate chips. When they melt, spread them with a knife or offset spatula.
Cool the brittle completely. You may need to refrigerate it to get the chocolate to set up. When cool, break into pieces to serve. Store in an airtight container at room temperature for up to 2 weeks, or freeze for up to 6 months.