Preheat oven to 375℉ and line a baking tray with parchment paper.
In a medium mixing bowl, mix sugar and cinnamon.
Slice the cake into 1 cm - 1 inch thick slices.
Cover both sides of each slice with the sugar mixture.
Place cake pieces on prepared baking sheet an inch apart.
Bake in preheated oven for around 10 minutes on one side, or until golden.
Flip the cake pieces and bake for another 10 minutes, or until dark golden brown.
Let cool on the baking tray or on a wire rack.