Let’s break down the process into easy-to-follow steps.

Make the Cake:

1. Preheat Oven: Preheat the oven to 350°F (175°C).
2. Whisk Dry Ingredients: Whisk together the flour, baking powder, baking soda, and salt in a medium bowl.
3. Combine Wet Ingredients: Whisk together the melted butter, olive oil, and sugar in a large bowl until combined.
4. Add Eggs: Add the eggs and whisk for 1 to 2 minutes, until lightened in color.
5. Add Remaining Wet Ingredients: Add the vanilla extract, buttermilk, lemon zest, and lemon juice, and whisk to combine.
6. Combine Wet and Dry: Add the flour mixture to the wet ingredients and whisk to combine. Be careful not to overmix.
7. Prepare Pans: Spray two 8-inch round cake pans with baking spray with flour. (Alternatively, butter and flour the pans). Divide the batter evenly between the prepared pans.
8. Tap Tap the pans a few times each on a kitchen towel on your counter-top to level the surface and remove air bubbles from within the batter.
9. Bake: Bake for 28 to 32 minutes, or until a toothpick inserted into the center comes out with only a few crumbs.
10. Cool. Transfer to a cooling rack. Let cool in the pans for 10 minutes, then turn out onto a cooling rack to cool completely, about 1 1/2 hours.  

Make the Frosting:

1. Cream Butter and Cream Cheese: Add the softened butter, cream cheese, and lemon zest to the bowl of an electric stand mixer fitted with the paddle attachment and beat on medium speed until creamy, about 2 minutes.
2. Add Powdered Sugar: Add the powdered sugar. Beat on low speed until combined. Increase the speed to medium and beat until smooth, about 1 minute.
3. Add Lemon Juice and Food Coloring: Scrape down the sides and bottom of the bowl. Add the lemon juice and yellow food coloring, if using. Beat until light and smooth, about 2 more minutes.

Assemble the Cake:

1. Level Cake Layers (Optional): Trim the cake layers to make the tops flat and even, as needed. This will create a more stable and visually appealing cake.
2. First Layer: Place 1 cake layer on a cake plate or stand. Spread 1 cup of buttercream evenly over the top.
3. Second Layer: Top with the second cake layer.
4. Frost Cake: Spread the remaining buttercream all over the top and sides of the cake, creating a smooth finish.
5. Garnish: Garnish with white chocolate curls, lemon slices, and/or edible flowers, if desired.

These steps are easy.