Process together berries, pecans and brown sugar into a paste in food processor and set aside.
For the remaining ingredients: Beat softened butter for 30 seconds. Add sugar, baking powder and salt and beat until combined. Beat in eggs. Add flour (may have to work in by hand). Divide dough in half and refrigerate for 1 hour. When chilled, roll each half into a 10" square. Spread with filling and roll up. Chill rolls for at least 4 hours. Slice into 1/4" cookies; placing on parchment paper to bake. Bake at 375 for 8-10 minutes. Edges should be firm and bottoms lightly browned.