Preheat oven to 350 degree and grease a 9x13 baking dish.

Combine cake mix, oil, eggs and sour cream in a medium bowl and beat using a stand mixer or hand mixer for about 2 minutes or until well combined.

In a small bowl, combine the palm sugar and cinnamon and set aside.

Pour half of the cake batter in the grease pan and spread evenly. Spread the cinnamon and sugar mix evenly over the surface, then pour the other half of the batter over the cinnamon and sugar and smooth the surface.

Bake for 45-50 minutes or until golden on the top and a toothpick comes out clean. Let cool for 10-15 mins.

While cake is cooling, combine all of the ingredients for the glaze and beat or whisk to fully incorporate the sugar into the milk and butter. Set aside.

Using a fork, gently poke the top of the surface of the cake all over then pour the glaze over the top being sure to coat the entire surface evenly.

Allow to finish cooling before serving.