Itty-Bitty Sandwich Cookies

Ingredients

• Cookies
• ½ cup (113 g) unsalted butter, at room temperature
• ½ cup (99 g) granulated sugar
• 1 large egg yolk
• 1 teaspoon pure vanilla extract
• 1½ cups (180 g) all-purpose flour
• ⅓ cup (28 g) cocoa powder
• ¼ teaspoon baking soda
• ¼ teaspoon fine sea salt
• Filling
• 4 tablespoons (57 g) unsalted butter, at room temperature
• 2 ounces (57 g) cream cheese, at room temperature
• 2 cups (227 g) confectioners’ sugar
• 1½ tablespoons heavy cream