Summarize the following:
Cornstarch will give you the best replica of cake flour. Using organic cornstarch will also give you the healthiest option. You could also use 1 tablespoon (14.8 ml) of arrowroot powder as an even healthier alternative for organic cornstarch. However, arrowroot is harder to use if you haven't baked with it before, and it changes your cake's texture and cooking time. Add spoonfuls of flour to top off the 1 cup, then level it off with the flat side of a knife. Oat and spelt flour are naturally lighter flours, which will help keep the cake fluffy. They're also healthier options—oat flour helps stabilize blood sugar and spelt flour is good for people with gluten sensitivity. You can also use white wheat flour, but then you'll need to add another 1 tablespoon (14.8 ml) (10 g) of cornstarch or arrowroot powder. This type of flour will also add a strong wheat flavor to whatever you're baking. Combine the 2 ingredients completely in order to fully aerate the flour.

Summary:
Measure 1 tablespoon (14.8 ml) (10 g) organic cornstarch into a 1 cup measuring cup. Fill up the rest of the 1 cup (78.75 g) with oat or spelt flour. Dump the ingredients into a mixing bowl and whisk them together.