I was going to suggest zucchini ribbons myself. I saute them briefly in garlic and olive oil before putting sauce on them and they are so delicious! I honestly think I like it even better than real pasta!

For long rides, I fuel with natural carbs (sweet potatoes, bananas, grapes...) or in a pinch, Lara bars but I don't have the carb sensitivities that others have. I just avoid grains and starches.

I don't know what to tell you about 'treats' as we can have things like honey or maple syrup in small quantities, so I have recipes that include those. I have found that no longer eating processed foods or sugar has made a HUGE difference in my taste buds though and now things like raspberries taste like candy to me. Super dark (85% cacao) chocolate is now plenty sweet for me, too. I even have recipes for sweet potato pie or a sweet potato snack cake for which I had to reduce the amount of honey in the recipe to almost nothing because my tastes have changed.

So yeah, not having sweet treats will be tough at first, but eventually, you get past that an just stop wanting them. At least, that was my experience (and again, I'm not really low carb...just reduced carb and no grains or starches).