1 cup unsalted butter, room temperature
1 cup powdered sugar, divided
1 large egg yolk
1 teaspoon pure vanilla extract
2 ½ cups all-purpose flour
6 ounces raspberry jam
2 teaspoons unsweetened lemon juice
1 teaspoon 2% milk
Step 1: Preheat oven to 375°F. Cover a cookie sheet with parchment or baking paper.
Step 2: In a large bowl, cream butter and ½ cup sugar together. Add egg yolk and vanilla; mix until light in color.
Step 3: Add flour, a little at a time, until dough is smooth. Divide into 3 equal balls. Roll each ball into a strand about ¾-inch thick and the length of prepared cookie sheet. Place about 2 inches apart on cookie sheet. With the side of your finger, press a groove down the center of the length of each strand.
Step 4: Bake for 20 minutes (firm to the touch). Remove from oven and spoon jam into grooves. Return to oven for 12-15 minutes or until light golden brown.
Step 5: While bars are hot, cut at a 45° angle into 1-inch pieces. Let cool completely on cookie sheets.
Step 6: Combine ½ cup sugar, lemon juice, and milk; mix until smooth. Drizzle icing.