-
Preheat your oven to 350F. Line an 8×8-inch baking pan with parchment or spray with oil.
-
In a small bowl, sift together the flour, baking powder, and salt, set aside.
-
Put the white chocolate chips in a heat-proof bowl.
-
Put the butter and sugar in a saucepan over low heat until the sugar has dissolved. Pour this mixture over the white chocolate chips; let stand for about 2 minutes. Use a rubber spatula to stir and make sure all the white chocolate chips melt. Let cool slightly before proceeding.
-
In a large mixing bowl, whisk the egg and extract together. Slowly whisk in the cooled chocolate mixture into the egg mixture. Add the dry ingredients and mix until just combined.
-
Pour batter into the prepared pan and use a spatula to spread it to the edges. Bake for 25-30 minutes or until a toothpick comes out clean. Allow to cool slightly before slicing.