Chop cranberries and pecans together with brown sugar until the mixture is combined and the pieces are very fine. (If you are making a double batch, you can do this in the food processor.)
For the Biscuits
In the bowl of your food processor, mix flour, baking powder, 2 teaspoon brown sugar, rosemary and cream of tartar. Pulse to combine.
Add butter and pulse until the mixture resembles wet sand.
Add milk and pulse until the dough is moistened.
Putting It All Together
Scoop 1 tablespoon of biscuit dough into each well of a greased, mini muffin pan. With moist fingers, press the biscuit dough up the sides of the well, forming a cup of dough.
Place roughly ½ teaspoon of brie (with or without the rind) into each biscuit 'cup'.
Top each brie section with ¼ teaspoon of the cranberry mixture.
Bake the bites for 10 minutes, until the biscuit is puffy and the cheese is bubbly.
Let cool for 5-10 minutes in the pan before removing from the pan to cool on a wire rack.
Serve warm or at room temperature.
Notes
*If using all purpose flour, you may need to add an extra Tablespoon or two of flour to the mixture.