Combine yeast, 1 tsp. sugar and warm water in the bowl of a stand mixer fitted with the dough hook attachment. Let sit for 5 minutes or until it begins to foam. Add 1/4 cup sugar, milk, 4 Tbsp. butter, egg and salt and mix until combined. On low speed, gradually add flour. Increase speed to medium high and mix for 7-8 minutes until dough comes together in a ball. Place the dough into a large bowl sprayed with non-stick cooking spray. Cover with a towel and let rise in a warm area until doubled in size, about 1 hour.
While dough is rising, prepare filling. In a medium bowl, combine brown sugar, cinnamon and butter until well blended.
Spray a 9x13 pan (or a 9-inch round pan) with non-stick cooking spray.
Preheat oven to 375 degrees.
On a generously floured work surface, roll dough out to a 12x18 rectangle by about 1/4 inch thick. Spread the filling mixture over dough. Sprinkle with the raisins, slightly pressing them into the dough. Starting at one long side, roll the dough carefully and tightly like a jelly roll to the other end, pinching the seam to seal. Cut the dough into 12 1 1/2 inch slices. Place in prepared pan. Cover with a damp towel and let rise again for 30 minutes or until doubled in size.
Bake for 20-25 minutes or until golden brown.
While rolls are baking make icing. Combine all ingredients in small bowl. Whisk together until smooth. Spread over warm rolls.