Preheat oven to 375˚F and grease a 9-inch round springform pan.
Combine all dry cake ingredients in a bowl and mix well, and combine all wet cake ingredients into a bowl and mix well. Then mix wet ingredients with dry and mix well.
Pour cake batter into the springform pan and bake in the oven for 30 minutes. Remove from the oven and allow to cool completely before frosting.
Melt chocolate for frosting in a saucepan over low heat (watching closely so it doesn't burn) or use a double boiler. Once melted, remove chocolate from heat and allow to cool.
Scrape chocolate into a bowl safe to use with a hand mixer, and add maple syrup and orange zest to the chocolate. Mix with a hand mixer until combined.
Checking first to make sure the chocolate is not hot enough to melt butter, add the butter to the chocolate mixture and beat until fluffy.
Frost chocolate cake with buttercream frosting before cutting and serving.