I love the texture of this cake which is almost like a very thick custard. The Grand Marnier gives it that wonderfully orange flavor. The consistency of this cake is very different than your typical cake. I took this to a meeting of 15 people and 12 really liked it and 3 really didn't like it at all. There didn't seem to be any in between likes about it. This recipe came from Food 52.
Heat oven to 350 F. Oil, butter, or spray a 9 inch cake pan that is at least 2 inches deep with cooking spray and line the bottom with parchment paper. (If your cake pan is less thn 2 inches deep, divide between 2 pans and start check for doneness at 30 minutes.) I didn't have parchment paper and just used the baking spray and it turned out fine.
In a bowl whisk the flour, sugar, salt, baking soda and powder. In another blow whisk the olive oil, milk, eggs, orange zest and juice and Grand Marnier.
Add the dry ingredients; whisk until just combined. Pour the batter in the prepared pan and bake for 1 hour, until the top is golden and a cake tester comes out clean.
Transfer the cake to a rack and let cool for 30 minutes. Run a knife around the edge of the pan, invert the cake onto the rack and let cool completely for 2 hours.