In a small bowl, whisk together the cornstarch and milk.
In a saucepan over medium-low heat, melt the coconut oil.
Add the coconut sugar and maple syrup.
Increase the heat to medium-high and bring the mixture to a gentle boil, constantly stirring.
Whisk in the cornstarch mixture.
Allow the caramel to boil for a minute or so, stirring constantly, then remove from heat.
Stir in the salt and vanilla.
Reserve 1/4 cup of the caramel sauce and set aside.
To the remaining caramel, stir in the pecans. Pour the pecan mixture over the crust.
Bake for another 20 minutes.
Allow to cool completely (this will take a few hours - you may want to refrigerate to ensure they cut nicely). Cut into 9 large squares or 16 smaller squares. Heat up the remaining caramel and serve with a drizzle of the caramel.