Melt butter in a saucepan set over medium heat. Once melted, whisk in brown sugar and corn syrup.
Bring to a boil and cook for 1 minute.
Transfer the hot butter-sugar mixture to a heat safe bowl and add in almond flour and salt.
Let mixture cool for 5 minutes and then add in vanilla and egg white, whisking to combine.
Let the cookie batter rest for 10 minutes. While the batter is resting, preheat your oven to 350°F and line 2 to 3 large cookie trays with parchment paper, set aside.
Use a teaspoon (not a table or soup spoon) to scoop and portion out the cookies, spacing cookies 3-inches apart (the cookies will spread while baking).
Bake for 7 to 9 minutes until golden around the edges. The butter near the edges and center will be bubbling up as the cookies bake, this is okay!
Allow the cookies to cool for 5 minutes on the cookie tray before transferring to a wire rack to cool completely. The cookies will dry and crispy up as they cool.
TO MAKE THE FILLING:
Combine chocolate and cream in a heat-safe bowl and microwave in 45-second intervals, stirring between each interval until the chocolate is completely melted. Stir in vanilla. Let the mixture cool for 10 minutes until it is thickened but still spreadable.
Spread the cooled down chocolate mixture onto one cookie and sandwich another cookie on top.
Serve and enjoy. These cookies last for 3 days at room temperature or a week refrigerated in an airtight container.
