In a large bowl, stir together starter, water and 1-1/2 cups of the flour. Cover loosely and leave at room temperature to proof at least 8 hours or overnight. When starter has proofed, mix the oil, sugar and eggs in a small bowl; add to the starter mixture. Stir in remaining 1-1/2 cups flour, salt, baking soda, and baking powder. Turn dough out onto a floured board and knead 5 to 8 minutes, or until smooth. Cover loosely and let rest about 10 minutes. Roll out dough into a rectangle approximately 8 x 18-inches. Brush entire surface with half of the melted butter.
In a small bowl, mix filling ingredients; sprinkle evenly over dough. Roll up along the 18" side, forming a log. Using a sharp knife dipped in flour, cut the roll into 24 pieces, then form into balls. Dip balls into remaining melted butter and place into a lightly greased bundt pan, stacking one on top of each other. Set in a warm place and let rise until doubled, 1 to 2 hours.
Bake at 375º for about 30 to 40 minutes. Remove from oven and flip pan upside down on serving plate. Mix together icing ingredients until desired drizzle consistency.