Preheat the oven to 350F and line 2, 8-inch cake pans with parchment paper.

In a large bowl, whisk together the butter, sugar and eggs until smooth. Whisk in orange liquor and vanilla extract. In a separate bowl, combine the dry ingredients: flour, baking powder and salt.

Sift the flour into the cake batter using a fine-mesh sifter, whisking after each addition. Alternate adding the flour with adding 1 cup milk. Whisk batter just until smooth. Divide cake batter evenly between the two pans and bake in preheated oven until center is set, about 35 minutes. Test by inserting a toothpick into the center; it should come out clean.

Remove baked cakes from pans and cool completely on wire racks. Once cakes are completely cooled, use a long serrated knife to split the layers in half, creating 4 layers.

Prepare the butter cream: whisk the butter on high speed for several minutes, until light and fluffy. Whisk in softened cream cheese until well incorporated. Add the orange liquor and orange food coloring. Begin adding the confectioner's sugar, 1 cup at a time; scrap down sides of bowl often.

To assemble the cake: soak each cake layer lightly with orange juice (can add more orange liquor along with the juice for more flavor). Spread a generous amount of frosting over each cake layer, then top with about 3 tablespoons of orange marmalade. Repeat for remaining cake layers, except the top layer.

Frost outside of the cake with a thin layer of frosting, sealing in the edges. Refrigerator for 20 minutes. Remove and frost with final layer of frosting, making sure to even off the top of the cake as much as possible. Set back into the refrigerator.

Meanwhile, prepare the chocolate ganache. Heat 1/4 cup cream in microwave until very hot, then add the chocolate chips and stir until completely melted. Let the ganache stand for a few minutes.

Pour ganache over the sides and top of cake; use a flat spatula to even off the top. Garnish with orange wedges. Keep cake refrigerated. Remove from refrigerator 30 minutes before serving to allow the butter cream to soften.