Authentic Mandelbrot

Step 1
Preheat oven to 350 degrees F (175 degrees C). Spread almonds onto a baking sheet and toast in preheated oven until fragrant, 6 to 8 minutes. Cool, then coarsely chop the almonds.

Step 2
Reduce oven temperature to 325 degrees F (165 degrees C). Grease a baking sheet.

Step 3
Combine butter, white sugar, brown sugar, vanilla extract, almond extract, lemon zest, and orange zest in a large bowl. Beat at medium speed with an electric mixer until well blended. Beat in eggs one at a time.

Step 4
Whisk together flour, baking powder, and salt. Add to butter-egg mixture and mix on low speed just until blended. Stir in chopped almonds.

Step 5
Divide dough in half. Grease hands to prevent sticking. On prepared baking sheet, shape each half into a flattened log, about 9 inches long, 2 1/2 inches wide, and 1 inch tall.

Step 6
Bake in preheated oven until light brown, about 25 minutes. Remove from oven and allow to cool 5 minutes. Slice logs diagonally into 1/2-inch-thick slices. Arrange slices flat on baking sheet. Bake until bottoms are lightly browned, about 10 minutes. Flip cookies and bake until other sides are lightly browned, about 10 minutes more.