Besan is chickpea flour, i.e. gram flour. My dad usually used it for making pakoras¹ or fried fish. Here is a recipe for sweet besan balls, aka besan ladoo.

1/4 cup ghee or oil (ghee obviously makes it better)
1 cup gram flour (besan)
1/2 cup powdered sugar
1 teaspoon finely crushed cardamom, i.e. cardamom powder
crushed nuts, e.g. almonds or pistachios

• Heat the ghee in a wide pan, add the flour and fry it on low heat until the oil separates and the mixture turns into a brownish paste. This may take 20 minutes, so be patient and keep stirring.
• Add the mixture to a bowl and let it cool down.
• Mix in the powdered sugar and cardamom and work it into ping pong-sized balls.
• Sprinkle the nuts on top and serve!