Preheat your oven to 350°F (175°C) and grease a 9-inch springform pan, then lightly flour it to prevent sticking.
In a bowl, whisk together 2 cups of all-purpose flour, 2 tsp of baking powder, ½ tsp of baking soda, 1 tbsp of cinnamon, and a pinch of salt.
In another bowl, whisk 3 eggs, 1 ½ cups of sugar, ½ cup of vegetable oil, and 1 tsp of vanilla extract until well combined.
Gradually add the dry mixture to the wet mixture, gently folding until just combined. It's okay if there are a few lumps.
Peel, core, and slice 3 medium apples. Gently fold the apple slices into the batter.
Pour the batter into the prepared pan and spread it evenly.
Bake in the preheated oven for 40-45 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool in the pan for 15 minutes, then transfer it to a wire rack to cool completely.