• Place flour, sugar, and salt in the bowl of a food processor and pulse to combine. (note if you don't have a food processor, you can do this in a large bowl).
• Pulse in the chilled cubed butter until mixture resembles coarse meal (if you're not using a food processor, use a pastry blender or your fingers to cut butter in).
• In a small bowl, lightly beat one egg and mix in milk. Pour this into the flour/butter mixture and pulse until dough just comes together. 
• Remove dough to lightly floured surface and knead a few times to bring together into a smooth disc. Wrap in plastic wrap and chill dough for about 30 minutes. 
• Roll dough to about ⅛" thickness (you can divide dough into two portions to make rolling out easier) and cut out rectangles about 5" by 3 ¼". Re-roll dough scraps to utilize all of the dough. You should get about 14 rectangles. Place rectangles on parchment paper-covered baking sheet and chill for another 30 minutes. 
• Pre-heat oven to 350 degrees.
• Spoon about a Tbsp of cherry lime jam to the center half of the rectangles and cover each with a remaining rectangle. Using a fork, crimp the edges of each pop tart and cut a couple slits in the middles to let air escape when baking. Lightly beat remaining egg in a small bowl and then brush each pop tart with egg wash. 
• Bake pop tarts for about 20 minutes, until they're just turning golden brown. Remove from oven and let cool in pan for a few minutes before moving to wire racks to cool completely.
• Once pop tarts are cooled, drizzle icing over the top and top with sprinkles, if desired.

Cherry Lime Jam

• Add all ingredients to a medium saucepan over medium-high heat. Stir occasionally while mixture comes to a boil. Reduce heat to medium-low.
• Let mixture simmer while occasionally stirring. If you want a jam that's less chunky, you can gently mash the mixture with a potato masher while it cooks. Let cook for about 20-25 minutes, until jam thickens and/or is at 220 degrees on a candy thermometer (you can also test it by placing a spoonful of the jam on chilled plate and then placing the plate back in the freezer. After a minute, remove the plate and gently touch the jam with your finger. If the jam is ready, it will wrinkle slightly when pushed. If it doesn't wrinkle, continue cooking).
• Remove from heat and transfer jam to a mason jar, seal, and place in fridge to cool completely. 

Cherry Icing

• Add cherries and milk to blender and process until fairly smooth (it's OK if there are still some pieces of cherry). 
• Add confectioners' sugar to a medium bowl and stir in about half the cherry mixture. Add more of the cherry mixture a Tbsp at a time until desired consistency is achieved (you likely won't need all of the cherry mixture).