Alfajores Cookies

Ingredients

• 4 cups milk
• 2 cups sugar
• 1/4 teaspoon baking soda
• Pinch cinnamon
• 1 tablespoon brandy
• 1 teaspoon freshly grated lemon zest
• 2 teaspoons pure vanilla extract
• 1 cup all-purpose flour
• 1 cup plus 1 tablespoon cornstarch
• 1 teaspoon baking powder
• 1/2 teaspoon fine sea salt
• 1/2 cup granulated sugar
• 1 stick plus 2 tablespoons unsalted butter, at room temperature
• 2 large egg yolks