-Spread the pecans evenly on a baking sheet and bake them in a 350-degree oven for approximately 7-10 minutes (they're ready when you start to smell them). Set aside to cool.
-Meanwhile, melt the butter over medium-low heat in a 3 quart, heavy-bottom saucepan.
-Add the corn syrup, brown sugar, and salt and cook, occasionally stirring, until all the sugar has dissolved.
-Gradually add in the sweetened condensed milk and cook and stir over medium-high heat until the mixture comes to a boil.
-Continue boiling the mixture, stirring frequently. Be patient as you'll be boiling and stirring for quite a while (approximately 15-18 minutes).
-Using a candy thermometer, continue boiling and stirring until the mixture reaches 248-degrees (firm ball stage) on a candy thermometer.
-Turn off the heat and stir in the pecans and vanilla extract until well combined.
-Carefully drop the caramel and nut mixture, by tablespoon measurements, onto parchment-lined baking sheets, spacing them about 2" apart.
-Refrigerate the candy until firm.
-Meanwhile, melt the chocolate chips and the shortening together in a microwave-safe bowl on half power for 20-second intervals, stirring until the chocolate is smooth and melted.
-Using a teaspoon, dollop each turtle with chocolate (or you can drizzle chocolate over the top using a piping bag or fork) and return the turtles back to the fridge to firm before serving.