Slice one orange as thin as you can.

In a pan, combine sugar and water (refer to the syrup measurements) and place on medium heat.

When the mixture starts to simmer, place your sliced oranges in the sugary syrup on low-medium heat while you prepare your cake mixture.

In a bowl, combine flour, baking powder, and salt.

In a separate bowl, beat your eggs until foamy. Add sugar and beat until the mixture doubles in size and becomes lighter in colour.

Add oil, orange juice, and mix until combined.

Add flour mixture in small batches and mix on low. Make sure not to over-mix.

Add vanilla, orange zest, and combine.

Line baking pan with baking paper. Place your orange slices at the bottom of the pan and pour your batter in.

Bake, in a preheated oven, until golden brown. Remove it from the oven and allow it to sit at room temperature for 10-15 minutes before you transfer it to cooling rack and brush with the leftover syrup you soaked your orange slices in.