Pinwheel Cookies

2 1/4 c. flour
1/2 tsp. baking soda
1/2 tsp. salt
1 stick butter, softened
1 c. sugar
2 eggs, at room temperature
1 tsp. vanilla
1 (1oz) square unsweetened baking chocolate, melted
1 tsp. lemon extract

In a small bowl, combine flour, baking soda, and salt. Stir or whisk gently to blend. In a medium bowl, with an electric mixer on medium speed, beat butter and sugar until light and fluffy. Beat in eggs and vanilla. Add flour to butter-sugar mixture and blend well. Divide dough in half between 2 bowls. Stir chocolate into one half; stir lemon extract into the other. Cover each bowl and refrigerate at least 1 hour, until firm. Roll out each piece of dough between 2 pieces of wax paper into an 8x12 inch rectangle. Place 1 rectangle on top of the other and roll up from a long side into a 12-inch roll. Wrap in wax paper and refrigerate until firm, at least 2 hours. Preheat oven to 350*. Using a sharp knife, cut dough into 1/4 inch slices. Arrange about 3 inches apart on ungreased baking sheets. Bake 8-10 minutes, until lightly browned. Let stand 5 minutes, then remove to a rack and let cool completely.

Makes about 48 cookies.