Lightly grease the pan (loaf pan, mini loaf pan, 8”x8” (20 cm x 20 cm), or 9”x9” (23 cm x 23 cm)) with butter. Mix the flour and baking powder together, then sieve. Add the salt and mix well. Set aside.
Use an electric hand mixer to beat the butter and sugar until well combined and pale yellow in color. Add the first egg and beat well after each addition until creamy, scraping down the sides for even mixing. Add the vanilla essence and mix well. Fold the flour into the batter and mix until combined. Finally, add the milk.
Pour the batter into the greased baking pan. Shake it lightly or use a spatula to even out the top of the batter. Add the blueberries on top in a single, even layer.
Bake until golden brown and cooked through, about 40-50 minutes. Use a cake tester to check if it’s cooked in the middle. If the top becomes too brown while the inside is still uncooked, cover the top with aluminum foil.
Remove the cake from the oven and let it cool on a wire rack for 10 minutes. Dust with powdered sugar (optional) and cut the cake into pieces.
Notes
Depending on the oven, it may take more than 40 to 50 minutes to bake the cake. To prevent the top of the cake from browning too fast, cover the top of the baking pan with a sheet of aluminum foil.