In a small bowl, combine 1 cup of warm water, 2 1/4 tsp of active dry yeast, and 1 1/2 tbsp of sugar. Allow this mixture to sit for about 5-10 minutes until it becomes frothy.
In a large mixing bowl, whisk together 3 cups of all-purpose flour, 1 tsp of salt, and 1 tsp of garlic salt.
Once the yeast has activated, pour the yeast mixture into the bowl with the dry ingredients. Add 2 tbsp of chopped jalapenos and 1 1/2 cups of shredded cheddar cheese. Mix until the dough begins to come together.
Turn the dough out onto a lightly floured surface and knead for about 5-7 minutes, until it is smooth and elastic.
Form the dough into a ball and place it in a greased bowl, covering it with a clean towel. Let it rise in a warm place for about 1 hour, or until it has doubled in size.
Once the dough has risen, punch it down and divide it into 8 equal pieces. Roll each piece into a ball and poke a hole through the center to form a bagel shape.
Bring a large pot of water to a boil and add 1 tbsp of brown sugar. Carefully drop the bagels into the boiling water, cooking them for about 1-2 minutes on each side. Remove them with a slotted spoon and place them on a parchment-lined baking sheet.
Preheat your oven to 425°F (220°C). Bake the bagels for 20-25 minutes, or until they are golden brown and sound hollow when tapped on the bottom.
Let the bagels cool on a wire rack before slicing. Enjoy them warm or toasted!