Bianca B. Brown was seven or eight years old when her baking journey began.She recalls spending hours in the basement of her grandparent’s South Shore home, learning how to make her grandmother’s signature sour cream pound cake.Ethel Skyles Alexander-Taylor, a former Illinois state senator and representative, had a large group of friends and “political family. Her gift to them during the holidays was to bake cakes,” Brown said.“She would say, ‘Hey baby girl, you just don’t want to …