Stir flour, baking powder, salt, baking soda and raisins together. Separately, fork-blend eggs and buttermilk, then add to dry ingredients. Stir until sticky batter is formed. Scrape batter onto well floured surface and knead lightly. Shape batter into ball, then place in round non-stick casserole that has been sprayed with cooking spray. Mark a cross in the center, using a sharp knife. Bake uncovered in preheated 350 degree oven for about 1 1/4 hours. Wait 10-15 minutes before attempting to remove bread from casserole, then cool on wire rack. If desired, cut loaf into quarters and then slice thinly.