Preheat oven at 350-degrees. Line a 13x9 inch baking pan with aluminum foil and apply nonstick spray or butter.
In a medium bowl, stir together the dry ingredients: flour, baking powder, cardamom, cinnamon, ground ginger, and salt.
In a big mixing bowl, beat the butter until its smooth. Add the brown sugar and mix, pausing to scrape the sides of the bowl, until the two are fluffy in texture. Beat in the eggs and vanilla.
Slowly add in the flour mixture until just combined, then sprinkle in the white chocolate and candied ginger pieces. Spread the batter in the prepared pan.
Bake for 30 minutes, until the middle passes the toothpick test. Cool to room temperature. Use the foil to lift the contents onto a cutting board to slice.
Store blondies in a sealed container between parchment or waxed paper layers. Blondies can be frozen for later enjoyment.
OM NOM NOM!