Preheat your oven to 350°F and grease a 9-inch round baking pan.
Peel and finely grate your carrots using a food processor or box grater. Aim for about 1 1/2 cups of grated carrots.
In a medium bowl, whisk together the granulated sugar, melted butter, and eggs until smooth. Stir in the grated carrots. Then, add the dry ingredients (flour, baking soda, cinnamon, and a pinch of salt) and mix until just combined. The batter will be thick.
In a small bowl, combine melted butter, flour, brown sugar, cinnamon, and a pinch of salt. Mix with a fork or your fingers until crumbly and pebble-like.
Spread the batter evenly into the prepared baking pan. Sprinkle the streusel topping generously over the batter. Bake for 30–35 minutes, or until the center is just set and a toothpick inserted comes out mostly clean.
For extra indulgence, mix 1/4 cup softened butter with 1/4 cup honey to create honey butter. Spread or dollop on warm slices of coffee cake.