Heat the oven to 175°C (350°F). Line a 20 cm square baking tin with baking paper, leaving some paper over the sides so the bars can be lifted out later.
Brown the butter for the crust. Melt it in a small pan over medium heat and cook, swirling the pan, until it turns golden brown and smells nutty, about 3 to 4 minutes. Pour it into a bowl and leave it to cool for 5 minutes.
Stir the flour, sugar, and salt into the cooled brown butter until a soft dough forms. Press it evenly into the bottom of the tin. Bake for 15 minutes, until the edges are lightly golden. Leave the oven on.
While the crust bakes, whisk the eggs, brown sugar, maple syrup, melted butter, orange zest, vanilla, and salt in a large bowl until smooth.
Stir in the chopped pecans and fresh cranberries. Pour the filling over the warm crust and spread it evenly.
Bake for 25 to 30 minutes, until the filling is set at the edges and only slightly wobbly in the centre. It will firm up as it cools.
Cool completely in the tin, at least 2 hours, then lift out with the paper and cut into 16 bars with a sharp knife. Wipe the knife between cuts for clean edges.