Prepare a large pan (9x13-inch/22x33cm or larger) by filling it with fresh, fluffy, clean snow. Pack it down firmly and smooth the top. Keep the pan outside if it's cool enough, or put it into the refrigerator or freezer to keep cold while you prepare the syrup.
Boil the maple syrup in a small saucepan over medium-high heat, until it hits the soft ball stage - the temperature reaches between 235-240℉ (113-115℃) on a candy thermometer - about 8 to 10 minutes.
Take the pot of hot syrup immediately outside to the pan of snow (or remove the snow pan from the fridge or freezer if making the candy inside) and pour a thin stream of hot syrup onto the snow in a 5-6-inch (12-15cm) strip. Lay the tip of a popsicle stick or twig onto one end of the syrup trail, then roll it up, wrapping the hardening syrup around the end of the stick. There will be bits of snow stuck to the candy - those will melt, leaving only candy on the stick.
Repeat quickly with the rest of the syrup before it hardens, making 12 to 15 maple syrup lollipops.
Eat the lollipops immediately or stick the handles into the snow to keep them from sticking together and eat within a few hours. Uneaten maple syrup lollipops can be individually wrapped with parchment paper, stuck into a bigger resealable bag, and frozen for a few days.
Notes
Make sure to use 100% pure maple syrup to make snow candy. A candy thermometer makes this process easy and guess-free. However, you can also boil the syrup to the soft ball stage - until it forms a soft ball if you drop a small amount of it (about ¼ teaspoon) into a glass of ice-cold water. This will take about 8-10 minutes for 1 cup of maple syrup in a small saucepan at medium-high heat, stirring constantly.Don't boil the syrup too long or it can burn.