Preheat your oven to 350° F. Grease and flour a 10-inch springform pan.
For the Crumb Streusel
Use a food processor to pulse the dry streusel ingredients along with the lemon zest. Add the butter and process until the streusel has a moist, sandy consistency. Add the walnuts if desired and pulse one or two more times. Set the mixture aside for later.
For the Buckle Batter
Use a medium-size mixing bowl and add the flour, baking powder, ginger, and salt. Stir it all together. In a separate large mixing bowl, cream the butter with an electric mixer. Then, add the sugar and beat it with the butter until light and fluffy, about 3 minutes. Mix in the honey, lemon zest, vanilla and eggs and beat until smooth. Fold in the dry flour mixture in alternating batches, while gradually adding the half and half. Fold in the apple chunks.
Pour the batter into the greased and floured pan, and smooth out the top with an offset spatula or tablespoon. Sprinkle the crumb streusel on top of the batter evenly. Place the pan on the center rack of your oven and bake for about 75 minutes, or until a toothpick inserted in the center comes out clean. Allow the buckle to cool for an hour before releasing it from the pan. Serve warm if possible, with our without your favorite topping.
You can make this apple buckle in any of the following pans: