Snickerdoodle bars

Batter 
115g butter, melted
1 egg
1/4 cup brown sugar
1/4 cup white sugar
1 teaspoon vanilla extract
1/3 cup oats
2/3 cup brown flour
1/4 teaspoon cream of tartar 

Sprinkling 
1/8 cup white sugar
2 teaspoons cinnamon

Preheat oven to 180C. Grease a 8-by-8-inch baking tray.

Melt butter. Cool slightly; add egg, sugar, vanilla, and beat until smooth. Add flour, oats and cream of tartar until just combined; pour into tray.

Combine the sprinkling sugar and cinnamon; sprinkle over the batter.

Bake for 25 minutes, or until done. Cool in tray for at least 15 min before slicing.