Homemade Toaster Tarts (Pop tarts)

Ingredients

• 2 1/2 cups all purpose flour
• 1 tbsp confectioner's sugar/icing sugar or 1 tsp regular white sugar
• 1 tsp salt
• 1/2 cup vegetable shortening
• 1/2 cup cold, unsalted butter
• 1 large egg
• 2 1/2 tbsp milk
• filling of your choice. Jam, cinnamon sugar, chocolate, nutella, etc.
• Sprinkles (optional)
• 1 cup confectioner's sugar/icing sugar
• 1 to 1 1/2 tbsp milk (add more if needed)
• 1/4 tsp vanilla