Butter Tart Squares - Get Cracking

Ingredients

• 175 ml unsalted butter, at room temperature
• 400 ml all-purpose flour
• 125 ml icing sugar
• 2 ml salt
• 2 eggs
• 250 ml dark brown sugar, packed
• 125 ml pure maple syrup
• 50 ml unsalted butter, melted
• 15 ml all-purpose flour
• 15 ml apple cider vinegar
• 5 ml vanilla extract