Preheat the oven to 350°F (175°C). Grease and flour a 9-inch round cake pan.
In a medium bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, nutmeg, and ginger until well combined.
In a large bowl, beat the granulated sugar, brown sugar, and eggs together until smooth and creamy.
Slowly add the vegetable oil and vanilla extract to the sugar and egg mixture, mixing until fully incorporated.
Gradually add the dry ingredients to the wet ingredients, mixing gently until just combined.
Fold in the grated carrots, chopped walnuts, and raisins until evenly distributed.
Pour the batter into the prepared cake pan and smooth the top with a spatula.
Bake for 35 minutes or until a toothpick inserted into the center comes out clean.
Remove the cake from the oven and let it cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.
While the cake is cooling, prepare the yogurt parfait by mixing the Greek yogurt, honey, and vanilla extract in a medium bowl until smooth.
To assemble the parfaits, cut the cooled carrot cake into small cubes.
In serving glasses or bowls, layer the yogurt mixture, carrot cake cubes, and granola, repeating layers until the glass is filled, ending with granola on top.
Serve immediately or refrigerate the parfaits for up to 2 hours before serving.