Preheat your oven to 350°F (176°C). Prepare three 8-inch cake pans by greasing them with non-stick baking spray and placing parchment circles at the bottom.

In a medium-sized bowl, combine the flour, baking powder, baking soda, and salt. Set this mixture aside.

In a large mixing bowl, combine the unsalted butter, vegetable oil, sugar, and vanilla extract. Use an electric mixer to beat until light in color and fluffy, about 2-3 minutes.

Add the eggs one at a time, mixing until mostly combined after each addition. Scrape down the sides of the bowl.

Add half of the dry ingredient mixture to the batter and mix until mostly combined. Then, add the milk, orange juice, and zest, mixing until smooth. Lastly, add remaining dry ingredients and mix just until combined.

Divide the batter among the prepared cake pans. Bake for 18-23 minutes until a toothpick comes out clean. Allow the cakes to cool in the pans for 2-3 minutes, then transfer to cooling racks.

Puree the raspberries in a food processor, then strain to remove seeds. In a bowl, combine cornstarch and water. In a saucepan, combine raspberry puree, cornstarch slurry, sugar, and lemon juice.

Cook the raspberry mixture over medium heat, stirring until thickened and at a gentle boil for about 8-10 minutes. Let it boil for 1 minute, then refrigerate until cool.

In a large mixing bowl, combine cream cheese and butter, and beat until smooth. Gradually add half the powdered sugar and vanilla, mixing until smooth before adding the remainder.

Divide frosting into two bowls. Add orange zest to one and raspberry filling to the other, mixing separately. Optionally add gel icing colors.

Combine fresh orange juice and powdered sugar for syrup.

Level the tops of cooled cake layers if needed. Place first layer on a serving plate, drizzle with 4 tbsp syrup, pipe a dam of orange frosting, and spread half the raspberry filling. Repeat with second layer and add the third layer on top.

Use remaining frosting to cover the cake, creating an ombre effect. Use an icing smoother for blending.

Pipe a decorative border on top with any remaining colored frosting and optionally decorate with fresh raspberries and orange slices.