Ingredients:

  • 1/2 cup (113g) unsalted butter, softened
  • 3/4 cup (150g) granulated cane sugar
  • 1 large egg, room temperature
  • 1 tablespoon vanilla extract
  • 1 1/2 cups (185g) all-purpose flour
  • 1 teaspoon cream of tartar
  • 1/2 teaspoon baking soda
  • 1/4 teaspoon sea salt
  • 2 tablespoons granulated sugar (for topping)
  • 1 tablespoon ceylon cinnamon

Instructions:

  1. Preheat your oven to 350°F (175°C). Line an 8x8 or 9x9 inch square baking pan with parchment paper, leaving an overhang for easy lifting.
  2. In a large mixing bowl, cream the softened butter and 3/4 cup sugar just until smooth using a spatula. Do not over-mix to avoid incorporating too much air.
  3. Stir in the egg and vanilla extract until well combined.
  4. Fold in the flour, cream of tartar, baking soda, and sea salt. Mix until no white streaks of flour remain and a thick, tacky dough forms.
  5. Transfer the dough to the prepared pan. Use a dampened spatula to press the dough into an even layer to ensure uniform baking.
  6. In a small bowl, whisk together the 2 tablespoons of sugar and 1 tablespoon of Ceylon cinnamon. Sprinkle this mixture evenly over the top of the dough.
  7. Bake for 22–25 minutes until the edges are slightly pulling away from the sides of the pan. Allow to cool completely before slicing into 16 bars.