Ingredients:

  • 2 tbsp granulated sugar
  • 1 tsp ground Saigon cinnamon
  • 1 cup unsalted butter, melted and cooled
  • 1 cup light brown sugar, packed
  • 1/2 cup granulated white sugar
  • 2 large eggs, room temperature
  • 2 tsp pure vanilla extract
  • 2 cups all-purpose flour
  • 1 tsp cream of tartar
  • 1/2 tsp baking soda
  • 1/2 tsp sea salt
  • 1 tsp ground Saigon cinnamon

Instructions:

  1. Preheat your oven to 350°F (175°C). Line an 8x8 inch square baking pan with parchment paper, leaving an overhang on two sides for easy removal.
  2. Whisk the melted butter with the brown sugar and white sugar vigorously until the mixture looks glossy and pale.
  3. Add the eggs and vanilla extract to the butter mixture. Whisk until the batter appears glossy and fully cohesive.
  4. In a separate small bowl, whisk together the flour, cream of tartar, baking soda, salt, and 1 teaspoon of Saigon cinnamon. Use a silicone spatula to fold these dry ingredients into the wet batter until just combined.
  5. Spread the thick dough into the prepared 8x8 pan, smoothing the surface with a spatula.
  6. Mix the topping ingredients (2 tbsp sugar and 1 tsp Saigon cinnamon) in a small ramekin. Sprinkle the mixture evenly over the top of the batter.
  7. Bake for 25 minutes until the edges are firm and the top forms a mahogany-colored, crackly crust. Allow to cool completely before slicing into 16 bars.