Makes about 4 1/2 dozen
1 1/2 cups (3 sticks) unsalted butter, room temperature
2 cups firmly packed light brown sugar
2 large eggs
2 Tablespoons water
2 Tablespoons vanilla extract
1 1/2 cups all-purpose flour
3/4 teaspoon baking powder
1/4 teaspoon ground cinnamon
1/4 teaspoon salt
2 1/2 cups rolled oats
1 1/2 cups chopped walnuts (about 6 ounces)
3/4 cup golden raisins
1/2 cup sweetened shredded coconut
Preheat oven to 325ºF.
Butter 10x14-inch rimmed cookie sheet.
Line bottom with parchment.
Using electric mixer, cream butter and brown sugar in large bowl until light.
Beat in eggs one at a time.
Beat in water and vanilla.
Combine flour, baking powder, cinnamon and salt in small bowl.
Add to butter mixture and stir just until combined.
Mix in rolled oats, walnuts, raisins and coconut (dough will be stiff).
Press dough evenly into prepared pan.
Bake until top is golden brown and dry to touch, about 35 minutes.
Cool in pan on rack 5 minutes.
Run small sharp knife around pan sides to loosen cake, then turn out onto rack and peel off paper.
Invert again onto another rack so top surface faces up, then cool.
Cut into bars.