In stand mixer bowl, add 2 1/2 cups flour, yeast, sugar and salt; mix well. In saucepan or microwave-safe dish, heat milk, water and shortening to 120-130°F (shortening does not need to melt). Add to flour mixture. Using a paddle attachment, blend on low speed for 30 seconds. Add eggs; beat on medium speed for 3 minutes.
Switch to dough hook attachment. Gradually stir in enough remaining flour to make a firm dough. Knead until smooth and elastic, about 5 minutes. (NOTE: For hand mixing: following above steps, mix ingredients in large mixing bowl using a wooden spoon or dough whisk. Knead on floured surface until smooth and elastic.) Place dough in lightly oiled bowl and turn to grease top. Cover; let rise until indentation remains after poking dough with finger down to second knuckle, about 1 hour.
Prepare filling: In a small bowl, mix together brown sugar, walnuts, cinnamon and maple flavoring; set aside.
Punch down dough. Divide dough into 2 equal parts. On lightly floured surface, roll out each half to 18x12-inch rectangle. Spread with maple syrup and sprinkle with prepared filling mixture. Starting with longer side, roll up. Pinch seam to seal. Place each roll seam-side down on greased cookie sheet, and form into a ring. Pinch edges to seal. With scissors, make cuts 1 inch apart through top of ring to 1 inch from bottom (don't cut all the way through). Alternate cut slices, gently bringing one to center and next to outside of ring. Cover; let rise in warm place until indentation remains after lightly touching.
Preheat oven to 375°F.
Bake for 20 to 25 minutes until golden brown. Cool completely on wire rack.
Make the glaze: In a small bowl, blend all ingredients until smooth.
Drizzle glaze over cooled ring and garnish with holiday fruits and a dusting of powdered sugar (optional). Serve warm or cold.