In a small bowl, beat the filling ingredients until blended. Set aside.
1 (8-ounce) package cream cheese, ½ cup sugar, 1 large egg, 2 teaspoons vanilla extract, Zest of 1 orange
Put the chocolate and butter in a microwave-safe glass bowl. Microwave for 30 seconds and stir. Repeat until the chocolate is mostly melted; two 30-second melts is usually enough. Remove the bowl from the microwave and set aside.
4 ounces dark chocolate, ½ cup butter
In a large bowl, beat the eggs and sugar.
4 large eggs, 2 cups sugar
Gradually add the flour and whisk to combine.
1½ cups flour
Stir in the nuts and chocolate chips if desired.
1 cup chopped nuts, ½ cup dark chocolate chips
Stir in the vanilla extract, mint extract, and chocolate mixture and mix to make a thick batter.
2 teaspoons vanilla extract, ½ teaspoon mint extract
Spread half of the batter evenly into a greased 8x8-inch baking pan.
Gently spread the filling mix over the batter.
Spoon the remaining batter over the filling and spread to cover.
Bake 45-50 minutes or until the filling is set. Cool on a wire rack for 1 hour. Refrigerate for at least 2 hours.
Cut into bars. Refrigerate leftovers. (If there are any!)