Boil the Raisins (Moisture Secret)
In a small saucepan, combine raisins and water; bring to a gentle boil over medium heat.
Stir in baking soda (it will foam — this is normal).
Remove from heat; let cool to lukewarm. Do not drain — you will use the liquid too.
Preheat and Prep
Preheat oven to 350°F (175°C).
Grease and lightly flour a 9×13‑inch (23×33 cm) baking pan.
Cream Butter and Sugar
In a large bowl, beat softened butter and granulated sugar together until light and fluffy, about 2–3 minutes.
Add vegetable oil and mix until combined.
Add Wet Ingredients
Add eggs one at a time, mixing well after each.
Stir in vanilla extract.
Fold in the raisin mixture (raisins + liquid) until combined.
Add Dry Ingredients
Stir in flour, cinnamon, cloves, and salt until just combined — do not overmix.
Gently fold in freshly grated carrots.
Pour Batter and Add Topping
Pour batter evenly into prepared pan; smooth with a spatula.
In a small bowl, mix chopped pecans, brown sugar, and chocolate chips.
Sprinkle crumb topping evenly over the batter.
Bake
Bake 35–40 minutes until a toothpick inserted in the center comes out clean or with a few moist crumbs.
Note: a melted chocolate chip on the toothpick is not unbaked batter — check the actual crumb.
If the topping browns too quickly, tent loosely with foil after 25 minutes.
Cool and Serve
Let cake cool completely in the pan on a wire rack before covering or slicing.
Cut into squares and serve directly from the pan.