Preheat oven to 175 degrees celsius (fan forced).
Grease and line a 20cm square slice tin with baking paper, allowing the edges to overhang.
To make the base sift the plain flour into a large bowl.
Add the brown sugar and butter.
Mix well until the mixture forms a dough.
Press the mixture firmly into the base of the slice tin.
Bake for 15-16 minutes.
In a large bowl whisk together the egg, brown sugar, maple syrup, vanilla extract and salt until pale and frothy.
Add the pecans and mix to combine.
Pour the pecan mixture over the top of the warm slice base and spread the nuts out evenly.
Bake in the oven for a further 15 minutes or until set in the middle.
Leave in the tin for 30 minutes to cool before placing onto a wire rack to cool completely.
Store in an airtight container for up to 5 days.