Preheat your oven to 350°F (175°C). If you're the type who skips preheating, we need to have a serious talk.
In a food processor, blend all crust ingredients until they form a dough that sticks together when pressed between your fingers. No food processor? Mix with a fork and then get in there with your hands. Consider it arm day.
Divide the dough evenly among 12 muffin cups or tartlet molds, pressing it into the bottom and up the sides. Pro tip: wet fingers make this less of a sticky situation.
Prick the bottoms with a fork (it's oddly satisfying) and bake for 10-12 minutes until just starting to turn golden. Don't wander off to check Instagram—these can burn quickly.
While the crusts are baking, make your filling. In a small saucepan, combine berries, maple syrup, and lemon juice. Bring to a simmer over medium heat.
Once simmering, mash about half the berries with a fork (anger management, kitchen edition), leaving some whole for texture. Stir in chia seeds and vanilla, then remove from heat.
Let the filling cool for about 5 minutes—it will thicken as the chia seeds work their gel-like magic.
When the crusts are done, let them cool for 5 minutes in the pan, then carefully remove to a cooling rack.
Spoon the filling into the cooled tart shells. If you're feeling fancy, arrange some additional fresh berries on top.
For the optional glaze, warm the apricot jam with a teaspoon of water until liquid, then gently brush over the berries for that professional patisserie shine.
Refrigerate for at least 15 minutes to set (if you can wait that long), then serve and accept the inevitable compliments graciously.