Preheat the oven to 375ºF (190ºC). Line a large baking sheet with parchment paper.
In a large bowl, whisk together the flour, sugar, baking powder and salt until well combined. Work the butter and the orange zest into the flour mixture with your fingertips or with a pastry blender until pea sized pieces are formed. Stir in the mini chocolate chips.
In a small bowl, whisk together the sour cream, heavy cream, orange juice and vanilla extract. Stir the sour cream mixture into the flour mixture just until a shaggy dough is formed. Do not over mix.
Scoop 1/4 cup-sized rounded portions of dough and place them about 2 inches apart onto the prepared baking sheet. (If your dough has become a bit warm, refrigerate the dough portions for 15 minutes, then proceed with the recipe. This will prevent excess spreading.) Brush the tops of the scones with heavy cream. Bake until golden brown, about 20-25 minutes. Transfer the scones to a cooling rack.