Preheat oven to 180•c and line a square baking tin with greaseproof paper. I used an 8x8 tin but you can use a 9x13 for a thinner base, depending on how chunky you like the shortbread to be.
Prepare crust by adding flour, sugar, cinnamon, salt and butter to a bowl and mixing with fingertips to form a fine crumb.
Press into prepared tin & bake for 10 mins, until the edges are just starting to turn golden. Remove from the oven and set aside while you prepare the topping.
Mix cornstarch and mylk in a medium bowl until frothy. Add sugar, agave, butter, vanilla and salt and whisk until smooth. Stir through the chopped pecans and mix until thoroughly coated.
Pour on top of the base and cook in the oven again for 25 mins, keeping a close eye that the topping doesn't burn at the edges. You can cover with foil for the last 5/10 mins if needed. Remove from the oven and allow to cool. Cut into bars and sprinkle with a little sea salt before serving.
