Preheat the oven to 350F (non-convection/not fan-assisted). Spray a 4x10-inch or 8 1/2 x 4 1/2-inch loaf pan with cooking or baking spray, then line it with parchment paper, allowing the sides to extend past the edges of the pan to use as handles later to remove the loaf. Set aside.
Make the topping by stirring together the brown sugar, orange zest and flour in a small bowl. Cut the 3 Tablespoons of butter into 5 or 6 pieces and add to the bowl. Use your fingertips to rub the butter into the mixture until the butter is no larger than pea-sized pieces. Stir in the pecans. Set aside.
In a medium bowl, whisk together the flour, baking powder, baking soda and salt. Set aside.
Make the batter by adding the room temperature butter and white sugar to the bowl of a stand mixer fitted with the paddle attachment or a large bowl with an electric beater. Cream together at medium speed for about 2 minutes. Add the egg and beat in. Add the orange zest and vanilla and beat in.
With the mixer on low speed, add about 1/3 of the flour mixture to the batter and mix in. Add 1/2 of the sour cream and mix in. Add half the remaining flour mixture, followed by the remaining sour cream and the last bit of flour mixture. Mix together just until combined. Do not over-mix.
Using a rubber spatula, fold in the chocolate chips.
Spoon the batter into the prepared loaf pan and level the top evenly. Scatter the crumb topping evenly over the top of the batter.
Bake the loaf in the preheated oven for 34-45 minutes or until a tester inserted in the centre of the loaf comes out clean. (A 4x10-inch loaf will bake more quickly while the 8 1/2 x 4 1/2-inch loaf will take a bit longer).
Remove from the oven and allow the loaf to cool in the pan for 15 minutes. Use the parchment paper to lift the cake from the pan to a cooling rack to cool completely.
Notes
Tips!
I love the combination of chocolate chip and orange, but if you aren't a fan, you can simply skip the orange and go with a straight-up chocolate chip coffee cake loaf.
Be sure to take the egg out of the fridge when you take the butter for the loaf out of the fridge so they are both at room temperature when mixing the batter.
It may seem a little squatty when spreading the batter into the loaf pan, but it will rise up nicely. It won't ever be a tall loaf though.
Be sure to read the notes above this Recipe Card, for more tips on making this recipe. You'll find substitution suggestions and step-by-step photos that you might find helpful.