I need help! (Caramel Walnut Torte)

There is something wrong with my all time favourite sweet recipe! This tart is something I don't make too often because I'm likely to carry it off, hide me and my tart in a dark corner and eat it all in one sitting.

That's pretty bad for someone who considers herself a real savory person. It's caramel, walnuts, chewy with a nice crust. Caramel. Chewy. Observation: caramel is like bacon. No really. It makes almost everything better. (oh..caramel and bacon pancakes...yum!)

Well, obviously I made it several times before, and I gave it away as many times, got rave reviews and wrote the recipe for the people that begged for it. I started a new recipe book and in copying and writing down the recipes I'd like to keep, I think I've made a mistake somewhere.

Now, it's not a sophisticated recipe, nothing fancy, just caramel and walnuts in a pate sucré crust but I love it and I want it back!

So, I'll give the recipe as I have it here, would you be so kind to take a look at it?

For the dough:

175 gr ap flour/pastry flour

150 gr soft white sugar

pinch of salt

125 gr cold butter in small pieces

Combine in the bowl of your food processor and pulse until mixture is crumbly and holds when pressed together. Divide in two and flatten into disks. Rest in fridge until thoroughly chilled. Roll out to line a 20 cm tart pan. Two rounds, one bottom and one top layer.

For the filling:

125 gr sugar

1 tbs hot water

125 ml single cream

100 gr walnuts, chopped

pinch of salt

knob of butter

In a heavy bottomed saucepan heat sugar until it's caramellized. Add 1 tbs of hot water (be careful for hot splatters) and add cream while stirring continuously. Add chopped walnuts and the knob of butter, leave on heat for two more minutes while stirring. Pour filling onto bottom layer, fold overhanging edge inwards and top with second layer. Pinch edges with a fork.

Bake in preheated oven (175C) for 45 minutes.

This is what happened! Flavour is still amazing but I need an electric drill to get it out, edges are very very toothbreaking hard. I happily ate a eehrm.. quarter while it was still luke warm but I fear the result when it's cold. Ouch!

What's wrong? Temperature? Too long in the oven? Caramel to dark to begin with? Or maybe it's the pan I baked it it. It's a tad too large, meaning that the layers are too thin to shield and support the caramel and caused overheating and leaking?