If using fresh mangoes, peel and chop the mangoes. Blend the mango pieces until smooth to make mango pulp.
In a blender, add the mango pulp, yoghurt, milk, sugar or honey, and cardamom powder. Blend until smooth and creamy. If you prefer a thinner consistency, add more milk as needed.
Taste the lassi and adjust the sweetness or thickness by adding more sugar, honey, or milk as desired.
Pour the mango lassi into glasses. Add ice cubes if you prefer it chilled. Garnish with fresh mint leaves if desired.
For a richer lassi, use full-fat yoghurt. If you like it extra creamy, you can add a scoop of vanilla ice cream while blending.