In a large mixing bowl, mix the flour bread flour, salt, baking soda, baking powder, brown sugar, and granulated sugar together.
Add the melted butter, eggs, and vanilla. Mix until combined. Mix in the chocolate chips.
Spread the batter into the prepared pan and smooth the top. Bake for 30 minutes. After 30 minutes, give the pan a little shake. If it jiggles in the middle, put the pan back in and try again every 5 minutes until there is no longer a jiggle.
Set aside to cool.
For The Caramel
Combine the sugar, brown sugar, and syrup in a medium saucepan on medium heat, stirring every few minutes to keep the sugar heating evenly, but don’t stir constantly. Cook until it becomes fluid and deep caramel color.
Add the butter off the heat (The mixture will bubble rapidly so be careful) stirring constantly with a whisk until combined completely into the sugar mixture. There should be no visible butter so whisk quickly to combine and keep whisking until it is thoroughly combined (This can take 3 or 4 minutes).
Very slowly stir in the heavy cream, vanilla, and salt until combines. Allow to cool before pouring over the cooled blondie base. Allow to cool completely.
Foe the chocolate topping
Melt the chocolate melt chocolate in a microwaveable bowl for 30 seconds at a time (stirring in between) until the chocolate is smooth and fluid.
Pour the melted chocolate over the caramel and set aside until the chocolate has cooled completely.
Cut into squares and serve.
You can line the pan with nonstick foil or baking paper, but I haven’t tried these methods and can’t guarantee you won’t run into problems. Just keep in mind, if you use a silicone pan that isn’t fitted with any sort of frame (which will be floppy when you hold it), make sure to put it on top of a cookie sheet before filling it to keep it stable and to avoid disaster when moving in and out of the oven.
Please note that the caramel recipe uses golden syrup which is an amber-colored syrup with a rich, deep sweetness that you can buy here on Amazon. (#paidlink). I love golden syrup and use it a lot, but it could be substituted with corn syrup.
When you are ready to slice the blondies, heat the knife before you cut it (be very careful not to touch it when slicing). The knife will easily go through the chocolate without cracking it and it will give the caramel that beautiful ooze. Your guests will love it!