Step 1

Preheat oven to 325 degrees F (165 degrees C). Line baking sheets with parchment paper.

Step 2

Sift together the flour, 1 1/2 teaspoon cinnamon, baking powder and salt, set aside. In a medium bowl, cream together the 2/3 cup sugar and butter. Beat in 1 egg, egg yolk and vanilla. Stir in the dry ingredients.

Step 3

On a lightly floured surface, divide dough into two pieces. Roll each piece into a log about 9 inches long and 1 1/2 inches wide. Place logs on the prepared baking sheet and flatten slightly. Brush with the beaten egg.

Step 4

Bake for 25 to 30 minutes in the preheated oven, until golden and firm to the touch. Cool for 15 minutes.

Step 5

On a cutting board, slice each log crosswise at a diagonal into 1/2 inch slices, using a serrated knife. Place back on the baking sheet, cut side down, and sprinkle with a mixture of the remaining cinnamon and sugar. Return to the oven for an additional 15 to 20 minutes, until toasted. Cool on wire racks, and store in an airtight container.