Preheat the oven to 400°F (200°C). Slice a sweet potato lengthwise into ¼-inch thick slices. Lightly brush both sides with a bit of olive oil and place on a parchment-lined baking sheet. Roast for 20–25 minutes, flipping halfway through, until tender and lightly golden at the edges.
1 slice sweet potato
While the sweet potato roasts, stir together the ricotta, lemon zest, and vanilla extract.
2 tbsp ricotta cheese, ¼ tsp lemon zest, ¼ tsp vanilla extract
Once the sweet potato slice is roasted and slightly cooled, spread the ricotta mixture on top.
Add raspberries, chopped walnuts, a sprinkle of cinnamon, and basil leaves.
4 raspberries, 1 tsp walnuts, 1 dash cinnamon, 1 tsp basil
Serve immediately for a warm version, or chill in the fridge for a refreshing, make-ahead snack.