Preheat the oven to 350°F (175°C)
Line a baking sheet with parchment paper
Mix flour, sugar, baking powder, and salt in a bowl
Beat eggs with vanilla extract in a separate bowl
Combine the wet and dry ingredients
Add nuts, chocolate chips, or dried fruit if desired
Knead the dough lightly until it comes together
Divide the dough in half
Shape each half into a long log on the baking sheet
Bake until lightly golden
Remove from the oven and let cool slightly
Reduce the oven temperature to 325°F (165°C)
Slice the logs diagonally into 1/2-inch pieces
Arrange the slices cut side down on the baking sheet
Bake again until crisp and golden
Flip the slices halfway through for even baking
Cool completely before serving or storing