Thoroughly wash raspberries, and then layer them in the jar interchangeably with the sugar. Start with raspberries, then generously cover with a few tablespoons of sugar. Repeat until you fill the entire jar.
Slowly pour the liquor into the jar over sugar and raspberries, as much as the jar will take. This process takes a few minutes as the alcohol needs time to work through the raspberries and sugar to reach the bottom of the jar, and then to fill it up to the top. When the jar is filled, secure the lid. Repeat the steps for the remaining jar(s).
Take the jars outside, and leave them in a relatively (or partially) sunny place for at least 40 days, and up to 2-2.5 months. (Think window sill, sunny countertop, balcony corner, etc.)
After it's fermented, strain the raspberry liqueur into glass bottles. (If you dislike the raspberry grit, place a gauze over the strainer so it can pick up the extra pieces as you strain.) Keep the remaining raspberries for desserts, or make a boozy jam out of them.
Serving: serve raspberry liqueur (malinovac liker, malinovača) with dessert, coffee, or as an aperitif. Storing: store for up to 2 years in a cool, dark place.