In a medium bowl, combine the cake flour and baking powder. Sift together and set aside.
In another bowl, whisk together the egg, mirin, sugar, honey, and water. Add the egg mixture to the dry ingredients and mix until very smooth. To test the batter, scoop it up with a whisk and let it fall back into the bowl. The batter should flow easily, and the lines should disappear quickly. If the batter is too thick, add water 1/2 tablespoon at a time until the desired consistency is reached.
Lightly oil a large nonstick frying pan using a paper towel. Heat over medium-low heat. Pour 1 tablespoon of batter from about 6 inches (15 cm) above the pan—the height helps the pancake spread evenly into a round shape. The batter should form a 3-inch (7.5 cm) circle. Repeat to make 2–3 pancakes at a time.
Cook until many bubbles appear on the surface and the edges look dry. Flip and cook the other side for about 1 minute. Repeat with the remaining batter to make about 10 pancakes. Let cool slightly.
While the pancakes are cooling, prepare the fillings. Slice the strawberries. Whip the heavy cream with sugar until stiff peaks form. Have the anko (sweet red bean paste) ready.
To assemble the dorayaki, spread anko onto one pancake. Pipe whipped cream on top, arrange sliced strawberries over the cream, then sandwich with another pancake.