For the Cake:
Preheat the oven to 350°F (175°C). Grease and flour three 8×2 inch round cake pans.
In a medium bowl, whisk together the cake flour, baking powder, baking soda, and salt. Set aside.
In another bowl, combine sour cream, orange juice, orange zest, vanilla bean paste, and orange extract. Blend with a fork and set aside.
In the bowl of a mixer, beat the softened butter on medium speed until smooth. Gradually add the sugar and continue mixing for 3-5 minutes until light and fluffy. If using orange coloring, add it at this stage.
Add the eggs one at a time, mixing until each yolk is fully incorporated.
With the mixer on low speed, alternate adding the flour mixture and the sour cream mixture, beginning and ending with the dry ingredients. Mix just until combined.
Divide the batter evenly between the three prepared pans. Smooth the tops with a spoon.
Bake for 25-30 minutes or until a toothpick inserted into the center comes out clean. Begin checking around the 25-minute mark.
Allow the cakes to cool for 5-10 minutes in the pans before transferring them to a wire rack to cool completely.
For the Frosting:
In a mixer, beat the softened butter on low to medium speed until smooth.
Add the softened cream cheese and beat until well combined.
Mix in the vanilla bean paste, orange extract, and salt.
Gradually add the confectioners’ sugar, mixing on low speed until blended. Continue mixing until the frosting is smooth and creamy. Optionally, add a small amount of orange coloring gel.
If the frosting is too soft, refrigerate for a few minutes to thicken before frosting the cake.
Frosting the Cake:
Spread frosting on top of the first cooled cake layer. Top with the second layer and repeat, finishing with the third layer.
Apply a thin crumb coat of frosting to the top and sides of the cake. Chill the cake in the freezer for 15 minutes (or longer in the refrigerator) to set.
Apply the final layer of frosting and decorate as desired. You can texture the frosting using a small offset spatula for a rustic finish.
Storing the Cake:
Store the cake in an airtight container in the refrigerator. Before serving, allow the cake to sit at room temperature for 2-3 hours to soften.