Preheat oven to 350 degrees. Place almonds on a baking sheet, and toast until golden brown and fragrant, about 10 minutes. Remove from oven, and set aside to cool.Advertisement
Butter a 10-by-15-inch rimmed baking sheet. Spread toasted almonds in an even layer on pan. Place sugar and water in a medium saucepan; stir to combine. Place over medium-high heat; bring to a boil, brushing down sides of pan with a pastry brush dipped in water to prevent crystals from forming. Once sugar is dissolved, cook without stirring until sugar is deep amber. Add lemon juice; immediately pour over almonds, coating with a thin layer. If caramel doesn't cover all the nuts, tilt pan slightly to distribute, or stir in nuts with a wooden spoon, being careful not to touch caramel or hot pan. Cool completely. Gently twist pan to release praline. Break into pieces. Store in an airtight container for up to 1 week.