Preheat oven to 350°F. Grease and flour a 9 x 13-inch pan. Mix flour, baking powder, baking soda and salt and set aside. Using an electric mixer, cream butter, oil and granulated sugar. Add eggs, one at a time. Combine milk, vanilla extract, orange juice, and orange zest in a small bowl and mix until well incorporated. Alternate adding flour blend and orange juice blend into the mixer until incorporated.
Pour batter into prepared pan. Bake for 25–35 minutes, until a tester inserted in the middle comes out clean.
Allow cake to cool while the glaze is prepared. In a saucepan, combine butter, orange juice and sugar, and simmer for 5 minutes until sugar is dissolved. Remove from heat and stir in orange zest and liquor, if using. Poke holes using a large skewer 1 inch apart throughout the cake. Pour the glaze slowly over the cake and allow it to absorb into the cake for 6 hours or overnight. Cut into squares and serve.