Preheat oven to 350°F/177°C.
Line 8″ x 8″ square pan with parchment paper.
In a large bowl, combine mochiko (glutinous rice flour), baking powder, and salt. Sift in hojicha powder. Whisk all the dry ingredients to combine.
In medium glass bowl, whisk together the egg, sugar, oil, and milk.
Pour the wet ingredients over top the dry ingredients.
Use a spatula and mix until everything is combined and there are no lumps.
Pour the batter into the prepared glass pan.
Tap the pan a few times gently to release any bubbles.
Place in the centre of the oven and bake at 350°F/177°C for approximately 40 minutes, or until a toothpick inserted comes out clean.
Remove, and let cool on a wire rack.
Slice into 16 small squares. Dust with additional hojicha powder.