Preheat the oven to 375ºF (190ºC). Line a 6-serving shallow jumbo muffin pan* with jumbo muffin liners.** Jumbo muffin liners will fit by pressing them around the inside bottom edges.
Set aside 1/2 teaspoon of flour for the mini chocolate chips. In a medium-sized bowl, whisk together the remaining flour, the baking powder, salt and baking soda until well blended.
In a large bowl, beat the butter and sugar together, with an electric mixer on medium speed, until pale and fluffy. Beat in the honey until combined. Beat in the egg, egg yolk and vanilla extract in 3 separate additions, making sure each addition is well incorporated before adding the next addition.
In a small bowl, whisk the milk and sour cream together until well blended. With the mixer on low speed or by hand, mix the flour mixture into the batter in 2 additions alternating with half of the milk mixture after each addition. Mix just until combined.
In a small bowl, toss the mini chocolate chips with the reserved 1/2 teaspoon of flour until the chips are evenly coated. Gently fold the mini chocolate chips into the batter.
Transfer the batter to the prepared baking pan, evenly distributing the batter and filling the cups about half full. Top each one with the crumb topping. Sprinkle on the reserved 1 tablespoon of mini chocolate chips.
Bake for 10 minutes, then turn the oven temperature down to 350ºF (180ºC) and continue baking until a toothpick inserted into the center of the cakes comes out clean, about 8-12 more minutes. Let the cakes cool in the pan for 5 minutes, then transfer them to a cooling rack to cool completely.