Preheat oven to 160°C.
In a bowl, mix together wheat flour, baking powder and baking soda. Sift the mix three times to incorporate air.
Add jaggery powder and milk powder and mix well.
Add melted butter, milk and vanilla essence.
Mix to form smooth batter.
Add a tsp of wheat flour to blueberries and mix to coat them evenly.
Pour the batter into a 7" square tin which is greased and lined with parchment. Add the blueberries in between the batter and some on top.
Top the batter with slivered almonds.
Bake in preheated oven for 40-45 minutes or until a tooth pick inserted comes out clean.
Let the cake cool for five minutes on the rack.
Flip it onto the wire rack, remove the parchment and flip it back so that the top of the cake remains on the top.
Allow it to cool completely.
Slice it up and serve.