Line a 9X13 baking pan with parchment paper. Lightly spray with oil. Set aside.

Whisk flour and salt together. Set aside.

Beat 1 cup of butter until creamy, and then add the granulated sugar gradually, beating until light and fluffy (about 5 minutes total). Beat in 1/2 teaspoon of vanilla. Add the flour in 3 additions, slowly mixing it in. Mix in 1/2 cup of miniature chocolate chips with the last bit of flour. Press into the prepared pan evenly and cover with plastic wrap.

Chill for 30 minutes.

After 15 minutes, preheat the oven at 350 F.

Bake the crust until it is just barely turning light golden brown at the edges and top, but is not fully cooked, about 25 minutes.

About 10 minutes into the baking, prepare the filling. Combine 1 cup of butter with the brown sugar and golden syrup in a heavy, medium-large sauce pan. Heat on medium heat, stirring occasionally, until it comes to a boil, at which point stop stirring. Reduce heat to medium low to low, and cook until a thermometer reaches 300 F (adjust temperature as needed to ensure that the filling is ready when the crust is ready). After it reaches 300 F, remove the sauce pan from the heat and stir in the cream, peanuts, 1/2 teaspoon of vanilla, and a pinch of salt. Pour the filling over the partially baked crust and return it to the oven.

Bake until the filling has darkened slightly, is bubbling all over and the edges have set, about 15 minutes.

Remove the pan from the oven and let it cool for 5 minutes. Sprinkle the remaining miniature chocolate chips all over the top of the crust.

Place on a cooling rack to cool completely. Slice when cool--these bars were fine at room temperature for me, but Wilson preferred them chilled.